MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Biomedical Microdevices' source. Sun, 21 Mar 2010 17:31:37 +0100 http://www.medworm.com/index.php?rid=3386343&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20300854%26dopt%3DAbstract Authors: Guan X, Zhang HJ, Bi YN, Zhang L, Hao DL Detection of pathogens was demonstrated in a polydimethylsiloxane (PDMS)/glass microfluidic chip with which microbead-based immunoseparation platform and the bioluminescence technology were integrated. Escherichia coli (E. coli) O157:H7 was used as the model bacteria. The microchamber in microfluidic chip was filled with glass beads coated with antibodies which could capture specific organism, and the capture efficiency of the chip for the bacteria was about 91.75% approximately 95.62%. Then the concentration of bacteria was determined by detecting adenosine triphosphate (ATP) employing bioluminescence reaction of firefly luciferin-lucifera-ATP on chip. The method allowed reliable detection of E. coli O157:H7 concentrations from 3.2 x 1... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3386343 Fri, 19 Mar 2010 00:00:00 +0100 3386343 http://www.medworm.com/index.php?rid=3386342&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20300855%26dopt%3DAbstract Authors: Zhou L, Liu JH, Ma F, Wei SH, Feng YY, Zhou JH, Yu BY, Shen J The use of ceramic nano-carriers containing anti-cancer drugs for targeted delivery that span both fundamental and applied research has attracted the interest of the scientific community. In this paper, a hydrophobic photodynamic therapy drug, hypocrellin A (HA), was successfully encapsulated in water-soluble amorphous silica nanocage (HANC) by an improved sol-gel method. These nanocages are of ultrasmall size, highly monodispersed, stable in aqueous suspension, and retain the optical properties of HA. Moreover, these nanocages can be effectively delivered, subsequently taken up by cancer cells and finally targeted to mitochondria. In addition, incubation time dependent photodynamic efficacy difference between HANC ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3386342 Fri, 19 Mar 2010 00:00:00 +0100 3386342 http://www.medworm.com/index.php?rid=3386341&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20300856%26dopt%3DAbstract This study reveals the potential of using compressed collagen gel as a scaffold for skin engineering. PMID: 20300856 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3386341 Fri, 19 Mar 2010 00:00:00 +0100 3386341 http://www.medworm.com/index.php?rid=3386340&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20300857%26dopt%3DAbstract Authors: Cioffi M, Moretti M, Manbachi A, Chung BG, Khademhosseini A, Dubini G In this paper, microfluidic devices containing microwells that enabled cell docking were investigated. We theoretically assessed the effect of geometry on recirculation areas and wall shear stress patterns within microwells and studied the relationship between the computational predictions and experimental cell docking. We used microchannels with 150 mum diameter microwells that had either 20 or 80 mum thickness. Flow within 80 mum deep microwells was subject to extensive recirculation areas and low shear stresses (<0.5 mPa) near the well base; whilst these were only presented within a 10 mum peripheral ring in 20 mum thick microwells. We also experimentally demonstrated that cell docking was significantl... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3386340 Fri, 19 Mar 2010 00:00:00 +0100 3386340 http://www.medworm.com/index.php?rid=3386339&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20300858%26dopt%3DAbstract Authors: Adewola AF, Lee D, Harvat T, Mohammed J, Eddington DT, Oberholzer J, Wang Y A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple pancreatic islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes. The fanned out design of the second generation device optimized the efficient mixing and uniform distribution of rapid alternating solutions in the perifusion chamber and allowed for the generation of reproducible glucose gradients. Simultaneous imaging of calcium influx and mitochondrial potential changes in response to glucose stimulation showed high signal-noise ratio and spatial-temporal resolution. These results suggest that this system can be used for detailed study of the end... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3386339 Fri, 19 Mar 2010 00:00:00 +0100 3386339 http://www.medworm.com/index.php?rid=3381667&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20237849%26dopt%3DAbstract Authors: Chen MC, Gupta M, Cheung KC We demonstrate a microfluidic system for long-term tumor cell culture and drug testing. Three-dimensional cell culture is critical in characterizing anticancer treatments since it may provide a better model than monolayer culture of tumor cells. Breast tumor cells were encapsulated within alginate which was gelled in situ within the microchannels. Tumor spheroid formation was observed several days after cell seeding, and various concentrations of doxorubicin were applied to the encapsulated cell aggregates. Drug effects on cell viability and proliferation were measured. In future, hydrogel-based microfluidic devices can comprise part of systems which replace labor intensive screening platforms currently implemented in the laboratory, and they addres... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3381667 Wed, 17 Mar 2010 00:00:00 +0100 3381667 http://www.medworm.com/index.php?rid=3374539&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20229178%26dopt%3DAbstract Authors: Bork T, Hogg A, Lempen M, Müller D, Joss D, Bardyn T, Büchler P, Keppner H, Braun S, Tardy Y, Burger J An implantable transducer for monitoring the flow of Cerebrospinal fluid (CSF) for the treatment of hydrocephalus has been developed which is based on measuring the heat dissipation of a local thermal source. The transducer uses passive telemetry at 13.56 MHz for power supply and read out of the measured flow rate. The in vitro performance of the transducer has been characterized using artificial Cerebrospinal Fluid (CSF) with increased protein concentration and artificial CSF with 10% fresh blood. After fresh blood was added to the artificial CSF a reduction of flow rate has been observed in case that the sensitive surface of the flow sensor is close to the sedimen... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3374539 Sat, 13 Mar 2010 00:00:00 +0100 3374539 http://www.medworm.com/index.php?rid=3355095&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20213215%26dopt%3DAbstract Authors: Christ KV, Williamson KB, Masters KS, Turner KT Despite the importance of cell adhesion in numerous physiological, pathological, and biomaterial-related responses, our understanding of adhesion strength at the cell-substrate interface and its relationship to cell function remains incomplete. One reason for this deficit is a lack of accessible experimental approaches that quantify adhesion strength at the single-cell level and facilitate large numbers of tests. The current work describes the design, fabrication, and use of a microfluidic-based method for single-cell adhesion strength measurements. By applying a monotonically increasing flow rate in a microfluidic channel in combination with video microscopy, the adhesion strength of individual NIH3T3 fibroblasts cultured for 24... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3355095 Tue, 09 Mar 2010 00:00:00 +0100 3355095 http://www.medworm.com/index.php?rid=3355096&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20213214%26dopt%3DAbstract In this report, we discuss the chemical synthesis and photoactive properties of the caged peptides as well as the subsequent binding of these peptides to our hydrogel base. We further demonstrate the ability of this modified hydrogel material to pattern fibroblast cells on the micron scale using near-UV light exposure through a patterned photomask to selectively switch areas of the hydrogel surface from cell non-adhesive to cell adhesive. The cells are found to adhere and proliferate along the developed line patterns for at least 2.5 days, demonstrating significantly enhanced pattern longevity in comparison with previously reported studies. PMID: 20213214 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3355096 Sat, 06 Mar 2010 00:00:00 +0100 3355096 http://www.medworm.com/index.php?rid=3340159&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204702%26dopt%3DAbstract Authors: Wang F, Burns MA A droplet-based microfluidic platform was used to perform on-chip droplet generation, merging and mixing for applications in multi-step reactions and assays. Submicroliter-sized droplets can be produced separately from three identical droplet-generation channels and merged together in a single chamber. Three different mixing strategies were used for mixing the merged droplet. For pure diffusion, the reagents were mixed in approximately 10 min. Using flow around the stationary droplet to induce circulatory flow within the droplet, the mixing time was decreased to approximately one minute. The shortest mixing time (10 s) was obtained with bidirectional droplet motion between the chamber and channel, and optimization could result in a total time of less than 1 s.... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3340159 Sat, 06 Mar 2010 00:00:00 +0100 3340159 http://www.medworm.com/index.php?rid=3340158&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204703%26dopt%3DAbstract Authors: Sollier E, Cubizolles M, Fouillet Y, Achard JL This paper presents promising microfluidic devices designed for continuous and passive extraction of plasma from whole human blood. These designs are based on red cells lateral migration and the resulting cell-free layer locally expanded by geometric singularities such as an enlargement of the channel or a cavity adjacent to the channel. After an explanation of flow patterns, different tests are described that confirm the advantages of both proposed singularities, providing a 1.5 and 2X increase in extraction yield compared to a reference device, for 1:20 diluted blood at 100 microL/min. Devices have also been successively optimized, with extraction yields up to 17.8%, and biologically validated for plasma extraction, with no prot... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3340158 Sat, 06 Mar 2010 00:00:00 +0100 3340158 http://www.medworm.com/index.php?rid=3330923&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20195765%26dopt%3DAbstract Authors: Ye N, Wang MW, Qin J, Lin B The human formyl peptide receptor (FPR) plays an important role in inflammation and immunity. Finding of specific agonists and antagonists of FPR may provide potential therapeutic agents for FPR related disorders. The binding of agonist by FPR induces a cascade of G protein-mediated signaling events leading to neutrophil chemotaxis, intracellualr calcium mobilization, FPR ligand uptake and so on. This work proposed a microfluidic-based method to characterize FPR-related cellular events in response to small peptides, N-formyl-Met-Leu-Phe (fMLF), in rat basophilic leukemia cell line RBL-2H3 expressing human FPR (RBL-FPR). The results showed that fMLF triggered chemotaxis, calcium mobilization and FPR ligand uptake in RBL-FPR cells, indicating the pote... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3330923 Tue, 02 Mar 2010 00:00:00 +0100 3330923 http://www.medworm.com/index.php?rid=3330922&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20195766%26dopt%3DAbstract Authors: Li H, Lai F A multiphysics model is developed in this paper for simulation of the volume transition mechanism of the smart hydrogel in response to the changes in the ionic strength of bathing solution as an important measure of the ionic concentration of that solution, which is termed the multi-effect-coupling ionic-strength-stimulus (MECis) model. In the present works, the ionic strength is treated as a main stimulus and incorporated into both the ionic convection-diffusion system in the Nernst-Planck flux and the fixed charge density equation characterized by Langmuir isotherm theory. Due to the diffusion and convection, the osmotic pressure is produced by the difference in the ionic concentration between the interior hydrogel and exterior solution, which drives the swelling... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3330922 Tue, 02 Mar 2010 00:00:00 +0100 3330922 http://www.medworm.com/index.php?rid=3312270&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20177790%26dopt%3DAbstract Authors: Liu L, Luo C, Ni X, Wang L, Yamauchi K, Nomura SM, Nakatsuji N, Chen Y We have developed a combined micro-channel and micro-well system for easy cell loading, culture and post-culture operation on a chip. To demonstrate the reliability of the system, on chip cell culture and differentiation were performed with different types of substrates made of culture dish, glass cover slide and polydimethylsiloaxe (PDMS). As expected, mouse embryo fibroblasts (MEF) showed different adhesion and growth rate on different substrates. When embryonic stem (ES) cells were co-cultured with MEFs, the formation of ES colonies is efficient on both glass and Petri dish, although PDMS could also be used. Finally, ES cell differentiation with neuron growth factors was performed on different substrates... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3312270 Tue, 23 Feb 2010 00:00:00 +0100 3312270 http://www.medworm.com/index.php?rid=3312269&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20177791%26dopt%3DAbstract Authors: Luo X, Shen K, Luo C, Ji H, Ouyang Q, Chen Y We have developed a microturbidostat for long time bacterial culture at constant density controlled by optical detection and integrated pneumatic valves. The device was fabricated by multilayer soft lithography and in-situ formation of an agarose filter. The culture chamber of bacteria was connected in one side to a single bacterial input-output channel and in another side to a nutrient channel in which the agarose filter was formed to ensure the diffusion of nutrients and metabolites without bacterial loss. The bacterial number in the culture chamber was determined by measuring the fluorescence intensity of GFP proteins of the bacteria and the redundant bacteria could be exported automatically through the input-output channel with ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3312269 Tue, 23 Feb 2010 00:00:00 +0100 3312269 http://www.medworm.com/index.php?rid=3312271&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20174872%26dopt%3DAbstract Authors: Bayer CL, Konuk AA, Peppas NA Human disease processes are often characterized by a deviation from the normal physiological concentration of critical biomarkers. The detection of disease biomarkers requires the development of novel sensing methods which are sensitive, specific, efficient and low-cost. To address this need, the ability of a device, which incorporates a film of polymer acid doped polyaniline, to respond to proteins at physiological pH and ionic strength was assessed. The conductive polymer was found to respond by changing conductivity in the presence of biomolecules, demonstrating a direct chemical to electronic transduction method. In future work, specificity can be incorporated into the system by integrating the conductive polymer with a protein selective film.... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3312271 Sat, 20 Feb 2010 00:00:00 +0100 3312271 http://www.medworm.com/index.php?rid=3291509&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20169413%26dopt%3DAbstract Authors: Lee Y, Park S, Park J, Koh WG We used an assembly of silica nanoparticles (SNPs) as a three-dimensional template for protein immobilization to prepare a protein microarray with enhanced protein loading capacity and detection sensitivity. SNPs were first modified with 3-aminopropyltriethoxysilane (APTES) for covalent immobilization of protein and micropatterned on poly(ethylene glycol)(PEG)-coated glass slides using elastomeric membranes with an array of holes. Proteins were selectively immobilized only on the SNP region, while the PEG regions served as an effective barrier to protein adsorption. Because of multi-layered SNPs that had curved surface, protein loading in the SNP micropattern was about six times greater than on a planar surface, as observed by fluorescence microsc... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3291509 Fri, 19 Feb 2010 00:00:00 +0100 3291509 http://www.medworm.com/index.php?rid=3263318&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20143164%26dopt%3DAbstract Authors: Evans AT, Chiravuri S, Gianchandani YB PMID: 20143164 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3263318 Tue, 09 Feb 2010 00:00:00 +0100 3263318 http://www.medworm.com/index.php?rid=3221078&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20107907%26dopt%3DAbstract This study reports a transparent indium tin oxide (ITO)-based microheater chip and its applicability for perfusion cell culture outside a cell incubator. The attempt of the proposed ITO microheater is to take the role of conventional bulky incubator for cell culture in order to improve integratability with the experimental setup for continuous/perfusion cell culture, to facilitate microscopic observation or other online monitoring activities during cell culture, or even to provide portability of cell culture operation. In this work, numerical simulation and experimental evaluation have been conducted to justify that the presented device is capable of providing a spatially uniform thermal environment and precise temperature control with a mild deviation of +/-0.2 degrees C, which is suitabl... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3221078 Thu, 28 Jan 2010 00:00:00 +0100 3221078 http://www.medworm.com/index.php?rid=3213227&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20101469%26dopt%3DAbstract In conclusion, results of the technical and clinical evaluation suggest that the presented device delivers microdialysate samples suitable for accurate and long term stable continuous glucose monitoring in blood. PMID: 20101469 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3213227 Tue, 26 Jan 2010 00:00:00 +0100 3213227 http://www.medworm.com/index.php?rid=3179275&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20077017%26dopt%3DAbstract Authors: Steedman MR, Tao SL, Klassen H, Desai TA Due to the retina's inability to replace photoreceptors lost during retinal degeneration, significant interest has been placed in methods to implant replacement cells. Polymer scaffolds are increasingly being studied as vehicles for cellular delivery to degenerated retinas. Previously, we fabricated poly(methyl methacrylate) thin film scaffolds that increased survival and integration of implanted retinal progenitor cells (RPCs). Additionally, these scaffolds minimized the trauma and cellular response associated with implantation of foreign bodies into mouse eyes. Here, we demonstrate that biodegradable polycaprolactone (PCL) thin film scaffolds can be fabricated with integrated microtopography. Microfabricated topography in a PCL thin f... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3179275 Thu, 14 Jan 2010 00:00:00 +0100 3179275 http://www.medworm.com/index.php?rid=3179274&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20077018%26dopt%3DAbstract We present a 2-layer based microfluidic concentration generator by a hybrid of a serial and a volumetric dilution for dose-response experiments in drug screening. The hybrid dilution method using 2-layer based microfluidic network significantly reduces the total number of cascaded serial dilution stages. The proposed strategy is capable of generating a large number of universal stepwise monotonic concentrations with a wide range of logarithmic and linear scales. We have studied an equivalent electrical circuit to that of the 2-layer based microfluidic network, where the only variable parameter is channel length. We have designed a microfluidic dilution generator simultaneously covering 14 doses with a combination of 4-order logarithmic and 4-point linear concentrations. The design has been... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3179274 Thu, 14 Jan 2010 00:00:00 +0100 3179274 http://www.medworm.com/index.php?rid=3172673&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20069375%26dopt%3DAbstract Authors: Fernández-Rosas E, Gómez R, Ibañez E, Barrios L, Duch M, Esteve J, Plaza JA, Nogués C Microchips can be fabricated, using semiconductor technologies, at microscopic level to be introduced into living cells for monitoring of intracellular parameters at a single cell level. As a first step towards intracellular chips development, silicon and polysilicon microparticles of controlled shape and dimensions were fabricated and introduced into human macrophages and mouse embryos by phagocytosis and microinjection, respectively. Microparticles showed to be non-cytotoxic for macrophages and were found to be localized mainly inside early endosomes, in tight association with endosomal membrane, and more rarely in acidic compartments. Embryos with microinjected micropar... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3172673 Wed, 13 Jan 2010 00:00:00 +0100 3172673 http://www.medworm.com/index.php?rid=3172675&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20066496%26dopt%3DAbstract Authors: Mahalanabis M, Do J, Almuayad H, Zhang JY, Klapperich CM Here we report the demonstration of an integrated microfluidic chip that performs helicase dependent amplification (HDA) on samples containing live bacteria. Combined chip-based sample preparation and isothermal amplification are attractive for world health applications, since the need for instrumentation to control flow rate and temperature changes are reduced or eliminated. Bacteria lysis, nucleic acid extraction, and DNA amplification with a fluorescent reporter are incorporated into a disposable polymer cartridge format. Smart passive fluidic control using a flap valve and a hydrophobic vent (with a nanoporous PTFE membrane) with a simple on-chip mixer eliminates multiple user operations. The device is able to detect... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3172675 Tue, 12 Jan 2010 00:00:00 +0100 3172675 http://www.medworm.com/index.php?rid=3172674&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20066497%26dopt%3DAbstract Authors: Zhao L, Wang Z, Fan S, Meng Q, Li B, Shao S, Wang Q Micro total analysis systems (-TAS) or labs-on-a-chip, have been spreading rapidly due to their desirable characteristics, including reductions in reagent consumption, space requirements and analysis time. This work aimed at establishing an integrated microfluidic system which can supply the cells with fresh medium of oxygen and nutrition continuously at a control flow rate mimicking the microenvironment in vivo. Human non-small cell lung cancer cell line SPCA1 was seeded in a microchip supplied with fresh medium at a constant rate of 15 mm/24 h controlled by a pump. The expression of P-gp for verapamil-pretreated or non-pretreated cells was assayed with immunofluorescence. Both groups cells were exposed to anticancer drug VP... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3172674 Tue, 12 Jan 2010 00:00:00 +0100 3172674 http://www.medworm.com/index.php?rid=3154736&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20058084%26dopt%3DAbstract Authors: Pandian RP, Meenakshisundaram G, Bratasz A, Eteshola E, Lee SC, Kuppusamy P Lithium naphthalocyanine (LiNc) is a crystalline material that has significant potential as a probe for EPR (electron paramagnetic resonance)-based biological oximetry (Pandian et al. J. Mater. Chem. 19:4138-4147, 2009a). However, implantation of LiNc crystals in tissues in raw or neat form is undesirable since dispersion of crystals in tissue may lead to loss of EPR signal, while also exacerbating biocompatibility concerns due to tissue exposure. To overcome these concerns, we have encapsulated LiNc crystals in an oxygen-permeable polymer, Teflon AF 2400 (TAF). Fabrication of TAF films incorporating LiNc particles (denoted as LiNc:TAF chip) was carried out using solvent-evaporation techniques. The EPR... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3154736 Fri, 08 Jan 2010 00:00:00 +0100 3154736 http://www.medworm.com/index.php?rid=3154735&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20058085%26dopt%3DAbstract Authors: Goyal S, Kim YT, Li Y, Iqbal SM Selective protein channels in cell and nuclear membranes act as gateways to control the passage of molecules across. The selectivity of these channels stems from attractive potentials of the binding sites in the transmembrane proteins. These channels can filter out small volume of solutions with high precision. Motivated from this phenomenon, we report biomimetic facilitated transport modality to selectively separate a target molecule from a mixture of molecules. The attractive potential is generated by specific antibodies immobilized inside 15 nm diameter polycarbonate nanochannels. Two proteins with similar physicochemical properties (Bovine Serum Albumin 66 kDa, and Human Hemoglobin 65 kDa) are chosen as model molecules. The protein molecules... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3154735 Fri, 08 Jan 2010 00:00:00 +0100 3154735 http://www.medworm.com/index.php?rid=3154737&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20054654%26dopt%3DAbstract We present a novel technique to design and mill conventional glass pipettes at specifically chosen angles and geometries. Focus ion beam milling by Ga+ ions yields extremely polished edges. Results from mouse embryo piercing correlate increased penetration rates with decreased pipette angle. Milled pipettes maintain structural integrity after repeated piercing. For the first time, the effects of unintentionally implanted Ga+ on embryo development are addressed. Optimum embryo development up to blastocyst stage after manipulation reveal little impact of residual implanted Ga+, suggesting biocompatibility and paving the way to introducing ion milling techniques in the biomedical device arena. The milling technique can be adequately tailored to specific applications and allows for mass produc... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3154737 Thu, 07 Jan 2010 00:00:00 +0100 3154737 http://www.medworm.com/index.php?rid=3149402&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20049640%26dopt%3DAbstract We present a novel micro-macro hybrid soft-lithography master (MMHSM) fabrication technique where microdevices having both microscale and macroscale features can be replicated with a single soft-lithography step. A poly(methyl methacrylate) (PMMA) master having macroscale structures was first created by a bench-top milling machine. An imprinting master mold having microscale structures was then imprinted on the PMMA surface through a hot-embossing process to obtain a PMMA master mold. A poly(dimethylsiloxane) (PDMS) master was then replicated from this PMMA master through a standard soft-lithography process. This process allowed both microscale (height: 3-20 mum, width: 20-500 mum) and macroscale (height: 3.5 mm, width: 1.2-7 mm) structures to co-exist on the PDMS master mold, from which f... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3149402 Tue, 05 Jan 2010 00:00:00 +0100 3149402 http://www.medworm.com/index.php?rid=3135944&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20041349%26dopt%3DAbstract Authors: Pješčić I, Tranter C, Hindmarsh PL, Crews ND In this article, low cost microfluidic devices have been used for simultaneous amplification and analysis of DNA. Temperature gradient flow PCR was performed, during which the unique fluorescence signature of the amplifying product was determined. The devices were fabricated using xurography, a fast and highly flexible prototype manufacturing method. Each complete iterative design cycle, from concept to prototype, was completed in less than 1 h. The resulting devices were of a 96% glass composition, thereby possessing a high thermal stability during continuous-flow PCR. Volumetric flow rates up to 4 microl/min induced no measurable change in the temperature distribution within the microchannel. By incorporating a p... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3135944 Wed, 30 Dec 2009 00:00:00 +0100 3135944 http://www.medworm.com/index.php?rid=3120658&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20033850%26dopt%3DAbstract Authors: Lee Y, Ferrari G, Lee SC Major histocompatibility complex (MHC ) epitope presentation is needed for robust adaptive immune responses. Core peptide binding motifs for class I and class II MHC are 8-10 amino acids long, containing two or more "anchor" residues. These binding motifs define epitope anchor amino acid content and spacing, and knowledge of them has facilitated emergence of polyepitope vaccines. However, polyepitopes can exhibit "junctional epitopes" (neoepitopes interfering with vaccine function) resulting from juxtaposition of authentic epitopes. We have developed an algorithm for consideration of polyepitope sequence in light of MHC motifs to exhaustively identify all junctional-free polyepitope designs for any given set of authentic epitopes, and in so doing disco... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3120658 Thu, 24 Dec 2009 00:00:00 +0100 3120658 http://www.medworm.com/index.php?rid=3120659&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20033299%26dopt%3DAbstract Authors: Patel AA, Thakar RG, Chown M, Ayala P, Desai TA, Kumar S Biophysical cues encoded in the extracellular matrix (ECM) are increasingly being explored to control cell behavior in tissue engineering applications. Recently, we showed that cell adhesion to microtopographical structures ("micropegs") can suppress proliferation in a manner that may be blunted by inhibiting cellular contractility, suggesting that this effect is related to altered cell-scaffold mechanotransduction. We now directly investigate this possibility at the microscale through a combination of live-cell imaging, single-cell mechanics methods, and analysis of gene expression. Using time-lapse imaging, we show that when cells break adhesive contacts with micropegs, they form F-actin-filled tethers that extend and ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3120659 Tue, 22 Dec 2009 00:00:00 +0100 3120659 http://www.medworm.com/index.php?rid=3041990&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19946751%26dopt%3DAbstract This study presents a planar valveless impedance-based micropump for biomedical applications comprising a lower glass substrate patterned with a copper micro-coil, a microchannel, an upper glass cover plate, and a PDMS diaphragm with an electroplated magnet on its upper surface. When a current is passed through the micro-coil, an electromagnetic force is established between the coil and the magnet. The resulting deflection of the PDMS diaphragm creates an acoustic impedance mismatch within the microchannel, which in turn produces a net flow. The performance of the micropump is characterized experimentally. The experimental results show that a maximum diaphragm deflection of 30 mum is obtained when the micro-coil is supplied with an input current of 0.5 A. The corresponding flow rate is fou... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3041990 Sat, 28 Nov 2009 00:00:00 +0100 3041990 http://www.medworm.com/index.php?rid=3041989&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19946752%26dopt%3DAbstract Authors: Bhagat AA, Kuntaegowdanahalli SS, Kaval N, Seliskar CJ, Papautsky I Flow cytometer is a powerful single cell analysis tool that allows multi-parametric study of suspended cells. Most commercial flow cytometers available today are bulky, expensive instruments requiring high maintenance costs and specially trained personnel for operation. Hence, there is a need to develop a low cost, portable alternative that will aid in making this powerful research tool more accessible. In this paper we describe a sheath-less, on-chip flow cytometry system based on the principle of Dean coupled inertial microfluidics. The design takes advantage of the Dean drag and inertial lift forces acting on particles flowing through a spiral microchannel to focus them in 3-D at a single position across th... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3041989 Sat, 28 Nov 2009 00:00:00 +0100 3041989 http://www.medworm.com/index.php?rid=3037148&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19943113%26dopt%3DAbstract Authors: Shimizu K, Sasaki H, Hida H, Fujita H, Obinata K, Shikida M, Nagamori E We have fabricated a simple Si-MEMS device consisting of a microcantilever and a base to measure active tension generated by skeletal muscle myotubes derived from murine myoblast cell line C2C12. We have developed a fabrication process for integration of myotubes onto the device. To position myotubes over the gap between the cantilever and the base without damage due to mechanical peeling or the use of an enzymatic reaction, we cultured myotubes on poly-N-isopropylacrylamide (PNIPAAm) as a sacrifice layer. By means of immune staining of alpha-actinin, it was confirmed that a myotube micropatterned onto the device bridged the gap between the cantilever and the base. After 7d differentiation, the myotube was... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3037148 Fri, 27 Nov 2009 00:00:00 +0100 3037148 http://www.medworm.com/index.php?rid=3037147&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19943114%26dopt%3DAbstract Authors: Chen L, Conlisk AT One recent application of nanopores is to use them as detectors and analyzers for fast DNA sequencing. To better understand the DNA electrokinetic transport through a nanopore, a hydrodynamic model is developed to investigate the flow field, the resistive forces acting on the DNA, the DNA velocity and the ionic current through the nanopore. The numerical results reveal the relation between the DNA velocity and various parameters such as nanopore surface charge and solution concentration. The model is validated by comparing the numerical results with the experimental data for both DNA velocity and ionic current through the nanopore. PMID: 19943114 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3037147 Fri, 27 Nov 2009 00:00:00 +0100 3037147 http://www.medworm.com/index.php?rid=3034142&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19937128%26dopt%3DAbstract Authors: Zhu G, Li X, Pu J, Chen W, Luo Q Slow oscillations in the hippocampus are correlated with memory consolidation and brain diseases. The characteristic firings of the hippocampal network in vitro are still poorly understood. Here, spontaneous oscillations (~0.004 Hz) were found in high-density hippocampal networks by multi-electrode arrays after 30 days in vitro. This kind of spontaneous activity was characterized by periodic synchronized superbursts, which persisted for approximately 60 s at long intervals. Additionally, 1-Hz stimulation (duration <120 s) could regulate these network-wide oscillatory activities by triggering the next synchronized superbursts prematurely. The results demonstrated that the slow oscillatory activities in hippocampal cultures could be regulated ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3034142 Tue, 24 Nov 2009 00:00:00 +0100 3034142 http://www.medworm.com/index.php?rid=3034144&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19936930%26dopt%3DAbstract Authors: Evans AT, Park JM, Chiravuri S, Gianchandani YB This paper describes an actively-controlled architecture for drug delivery systems that offers high performance and volume efficiency through the use of micromachined components. The system uses a controlled valve to regulate dosing by throttling flow from a mechanically pressurized reservoir, thereby eliminating the need for a pump. To this end, the valve is fabricated from a glass wafer and silicon-on-insulator wafer for sensor integration. The valve draws a maximum power of 1.68 microW (averaged over time); with the existing packaging scheme, it has a volume of 2.475 cm(3). The reservoirs are assembled by compressing polyethylene terephthalate polymer balloons with metal springs. The metal springs are fabricated from Elgiloy(R... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3034144 Fri, 20 Nov 2009 00:00:00 +0100 3034144 http://www.medworm.com/index.php?rid=3034143&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19936931%26dopt%3DAbstract Authors: Evans AT, Chiravuri S, Gianchandani YB This paper describes a system for transferring power across a transdermal needle into a smart refill port for recharging implantable drug delivery systems. The device uses a modified 26 gauge (0.46 mm outer diameter) Huber needle with multiple conductive elements designed to couple with mechanical springs in the septum of the refill port of a drug delivery device to form an electrical connection that can sustain the current required to recharge a battery during a reservoir refill session. The needle is fabricated from stainless steel coated with Parylene, and the refill port septum is made from micromachined stainless steel contact springs and polydimethylsiloxane. The device properties were characterized with dry and wet ambient conditio... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3034143 Fri, 20 Nov 2009 00:00:00 +0100 3034143 http://www.medworm.com/index.php?rid=3009352&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19924539%26dopt%3DAbstract We report a novel and facile method for fabricating coaxial microfluidic devices processing various dimensions at low cost, in which polypropylene hollow fibers or glass capillaries are used as the tip of the dispersed phase injection tube. With this coaxial microfluidic device, monodisperse biocompatible microspheres ranging from 300 to 800 mum were obtained by collecting oil-in-water or water-in-oil emulsions and solidifying the suspended microspheres. Microsphere size could be controlled by changing the tips or tuning the concentrations of the dispersed and continuous phases. By adding functional nanoparticles into the dispersed phase, it was demonstrated that fluorescent and magnetic microspheres can be fabricated easily using these microfluidic devices. PMID: 19924539 [PubMed - as... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=3009352 Thu, 19 Nov 2009 00:00:00 +0100 3009352 http://www.medworm.com/index.php?rid=2935715&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19859812%26dopt%3DAbstract We describe a simple and reliable fabrication method for producing multiple, manually activated microfluidic control valves in polydimethylsiloxane (PDMS) devices. These screwdriver-actuated valves reside directly on the microfluidic chip and can provide both simple on/off operation as well as graded control of fluid flow. The fabrication procedure can be easily implemented in any soft lithography lab and requires only two specialized tools-a hot-glue gun and a machined brass mold. To facilitate use in multi-valve fluidic systems, the mold is designed to produce a linear tape that contains a series of plastic rotary nodes with small stainless steel machine screws that form individual valves which can be easily separated for applications when only single valves are required. The tape and it... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2935715 Tue, 27 Oct 2009 00:00:00 +0100 2935715 http://www.medworm.com/index.php?rid=2924633&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19851872%26dopt%3DAbstract Authors: Liao CY, Su YC We have successfully demonstrated the formation of biodegradable microcapsules utilizing PDMS double-emulsification devices. Specially designed 3D PDMS microchannels with surfaces selectively modified by a self-aligned photografting process are employed to generate monodisperse water-in-organic-solvent-in-water (W/O/W) emulsions in a controlled manner. Mainly by varying the outer and inner fluid flow-rates, the dimensions of resulting double emulsions can be adjusted as desired. Meanwhile, biodegradable materials are dissolved in the middle organic solvent (in this work ethyl acetate is used), and solidified into microcapsules once the solvent is extracted. In the prototype demonstration, microcapsules made up of poly(L-lactic acid), trilaurin, and phosphocholin... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2924633 Fri, 23 Oct 2009 00:00:00 +0100 2924633 http://www.medworm.com/index.php?rid=2912916&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19838804%26dopt%3DAbstract Authors: Zordan E, Amirouche F, Zhou Y This paper deals with the design and characterization of an electromagnetic actuation micropump with superimposed dual chambers. An integral part of microfluidic system includes micropumps which have become a critical design focus and have the potential to alter treatment and drug delivery requirements to patients. In this paper, conceptual design of variable geometrical nozzle/diffuser elements, coaxial cantilever valve, is proposed. It takes advantages of cantilever fluctuating valves with preset geometry to optimize and control fluid flow. The integration of this conceptual valve into a dual chamber micropump has increased the flow rate when compared to a single chamber micropump. This technique also allows for the fluid flow to be actively con... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2912916 Fri, 16 Oct 2009 23:00:00 +0100 2912916 http://www.medworm.com/index.php?rid=2902248&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19830565%26dopt%3DAbstract Authors: Chueh BH, Zheng Y, Torisawa YS, Hsiao AY, Ge C, Hsiong S, Huebsch N, Franceschi R, Mooney DJ, Takayama S This paper describes a simple reversible hydrogel patterning method for 3D cell culture. Alginate gel is formed in select regions of a microfluidic device through light-triggered release of caged calcium. In the pre-gelled alginate solution, calcium is chelated by DM-nitrophen (DM-n) to prevent cross-linking of alginate. After sufficient UV exposure the caged calcium is released from DM-n causing alginate to cross-link. The effect of using different concentrations of calcium and chelating agents as well as the duration of UV exposure is described. Since the cross-linking is based on calcium concentration, the cross-linked alginate can easily be dissolved by EDTA. We also de... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2902248 Wed, 14 Oct 2009 23:00:00 +0100 2902248 http://www.medworm.com/index.php?rid=2902247&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19830566%26dopt%3DAbstract Authors: Chung CK, Chang HC, Shih TR, Lin SL, Hsiao EJ, Chen YS, Chang EC, Chen CC, Lin CC The glass-based microfluidic chip has widely been applied to the lab-on-a-chip for clotting tests. Here, we have demonstrated a capillary driven flow chip using the water-assisted CO(2) laser ablation for crackless fluidic channels and holes as well as the modified low-temperature glass bonding with assistance of adhesive polymer film at 300 degrees C. Effect of water depth on the laser ablation of glass quality was investigated. The surface hydrophilic property of glass and polymer film was measured by static contact angle method for hydrophilicity examination in comparison with the conventional polydimethylsiloxane (PDMS) material. Both low-viscosity deionized water and high-viscosity whole blo... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2902247 Wed, 14 Oct 2009 23:00:00 +0100 2902247 http://www.medworm.com/index.php?rid=2888114&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19823934%26dopt%3DAbstract Authors: Bhattacharjee B, Najjaran H Research on so called digital microfluidic systems (DMS) capable of manipulating individual microdroplets on a cell-based structure has enormously increased in the past few years, mainly due to the demand of the technology-dependent biomedical applications. Significant research in this area has been related to the simulation and modeling of droplet motion, demonstration of different drop actuation techniques on laboratory-scale prototypes, and droplet routing and scheduling for more efficient assay procedures. This paper introduces the basics of the control analysis and design of a DMS, which is a relatively unexplored area in digital microfluidics. This paper starts with a discussion on a simplified dynamic model of droplet motion in a planar array... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2888114 Mon, 12 Oct 2009 23:00:00 +0100 2888114 http://www.medworm.com/index.php?rid=2872615&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19809878%26dopt%3DAbstract Authors: Zhang H, Shu D, Browne M, Guo P A customized laser combiner was designed and constructed for dual channel single molecule imaging. The feasibility of a combiner-incorporated imaging system was demonstrated in studies of single molecule FRET. Distance rulers made of dual-labeled dsDNA were used to evaluate the system by determining the distance between one FRET pair. The results showed that the system is sensitive enough to distinguish between distances differing by two base pair and the distances calculated from FRET efficiencies are close to those documented in the literature. The single molecule FRET with the dual-color imaging system was also applied to reconstructed phi29 motor pRNA monomers. Finally, techniques for dual laser alignment and tuning of laser power for dual-c... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2872615 Tue, 06 Oct 2009 23:00:00 +0100 2872615 http://www.medworm.com/index.php?rid=2872616&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19806459%26dopt%3DAbstract We present in this paper the implementation of an innovative three dimensional (3D) microfabrication technology coupled with numerical simulation to enhance the mass transport in 3D cell culture. The core of this microfabrication technology is a high-resolution projection micro stereolithography (PmuSL) using a spatial light modulator as a dynamic mask which enables a parallel fabrication of highly complex 3D microstructures. In this work, a set of poly (ethylene glycol) microfabricated bioreactors are demonstrated with PmuSL technology. We observed both experimentally and numerically the regulation of metabolism and the growth of yeast cells by controlling the density of micro-capillaries. Further development of these 3D microfabricated bioreactors is expected to provide artificially cons... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2872616 Mon, 05 Oct 2009 23:00:00 +0100 2872616 http://www.medworm.com/index.php?rid=2866159&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19802699%26dopt%3DAbstract Authors: Shao J, Wu L, Wu J, Zheng Y, Zhao H, Lou X, Jin Q, Zhao J Endothelial cell monolayer (EM), acting as a barrier between blood and tissue, plays an important role in pathophysiological processes. Here we describe a novel microfluidic chip that is applied for convenient and high throughput in vitro permeability assays of EM. The chip included a gradient generator and an array of cell culture chambers. A microporous membrane as a scaffold component was built between a polydimethylsiloxane (PDMS) layer and a glass substrate to grow EM. Cell culture chambers were separated by microchannels and microvalves. The concentration gradient of compound solutions could be generated automatically and affected EM in different chambers. The permeability of EM at different time with histamine st... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2866159 Fri, 02 Oct 2009 23:00:00 +0100 2866159 http://www.medworm.com/index.php?rid=2856244&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19795211%26dopt%3DAbstract Authors: Bandodkar AJ, Dhand C, Arya SK, Pandey MK, Malhotra BD Nanostructured polyaniline (PANI) film electrophoretically fabricated onto indium-tin-oxide (ITO) coated glass plate has been utilized for development of an immunosensor based on capacitance change of a parallel plate capacitor (PPC) by covalently immobilizing anti-human IgG (Anti-HIgG) using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide chemistry. These fabricated PANI/ITO and Anti-HIgG/PANI/ITO plates have been characterized using scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and Fourier transform infra-red studies. The capacitance measurements indicate that dielectric medium of this biologically modified PPC (Anti-HIgG/PANI/ITO) is sensitive to HIgG in 5 - 5 ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2856244 Wed, 30 Sep 2009 23:00:00 +0100 2856244 http://www.medworm.com/index.php?rid=2847429&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19787454%26dopt%3DAbstract Authors: Zhang W, Yang G, Zhang A, Xu LX, He X The morphological changes of small (~100 microm) alginate microcapsules and the biophysical alterations of water in the microcapsules during cryopreservation were studied using cryomicroscopy and scanning calorimetry. It was found that water in the small microcapsules can be preferentially vitrified over water in the bulk solution in the presence of 10% (v/v) or more dimethylsulfoxide (DMSO, a cryoprotectant), which resulted in an intact morphology of the microcapsules post cryopreservation with a cooling rate of 100 degrees C/min. A small amount of Ca(2+) (up to 0.15 M) was also found to help maintain the microcapsule integrity during cryopreservation, which is attributed to the enhancement of the alginate matrix strength by Ca(2+) rather... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2847429 Mon, 28 Sep 2009 23:00:00 +0100 2847429 http://www.medworm.com/index.php?rid=2847428&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19787455%26dopt%3DAbstract Authors: Borenstein JT, Tupper MM, Mack PJ, Weinberg EJ, Khalil AS, Hsiao J, García-Cardeña G Functional endothelialized networks constitute a critical building block for vascularized replacement tissues, organ assist devices, and laboratory tools for in vitro discovery and evaluation of new therapeutic compounds. Progress towards realization of these functional artificial vasculatures has been gated by limitations associated with the mechanical and surface chemical properties of commonly used microfluidic substrate materials and by the geometry of the microchannels produced using conventional fabrication techniques. Here we report on a method for constructing microvascular networks from polystyrene substrates commonly used for tissue culture, built with circular cross-sectio... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2847428 Mon, 28 Sep 2009 23:00:00 +0100 2847428 http://www.medworm.com/index.php?rid=2847427&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19787456%26dopt%3DAbstract Authors: Modak N, Kejriwal D, Nandy K, Datta A, Ganguly R Magnetophoretic isolation of biochemical and organic entities in a microfluidic environment is a popular tool for a wide range of bioMEMS applications, including biosensors. An experimental and numerical analysis of magnetophoretic capture of magnetic microspheres in a microfluidic channel under the influence of an external field is investigated. For a given microfluidic geometry, the operating conditions for marginal capture is found to be interrelated in such a manner that a unique critical capture parameter [Formula: see text], that is proportional to the ratio of the magnetic force to viscous force, can be identified. Influences of the flow rate, magnetic field and other parameters on the particle trajectories in the microfl... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2847427 Mon, 28 Sep 2009 23:00:00 +0100 2847427 http://www.medworm.com/index.php?rid=2832553&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19777351%26dopt%3DAbstract Authors: Lee DH, Park JY, Lee EJ, Choi YY, Kwon GH, Kim BM, Lee SH In this paper, we propose a method to construct three-dimensional curved microstructures with easy control of the size, position and shape, by exploiting the elasticity of poly(dimethylsiloxane) (PDMS) membranes and basic physics. For this end, we developed the method to handle thin PDMS membrane safely, and to replicate PDMS microstructure from the PDMS mold. Using this method, we demonstrated two potential applications: (1) the use of concave well for the formation of embryoid body (EB) to differentiate into neuronal cells, and (2) the fabrication of SU-8 and hydrogel microparticles having diverse curved shapes. The curved structures were successfully fabricated with simple process, and EBs were formed in the concave ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2832553 Wed, 23 Sep 2009 23:00:00 +0100 2832553 http://www.medworm.com/index.php?rid=2824913&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768547%26dopt%3DAbstract Authors: Liu X, Sun Y PMID: 19768547 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2824913 Fri, 18 Sep 2009 23:00:00 +0100 2824913 http://www.medworm.com/index.php?rid=2805150&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757070%26dopt%3DAbstract In this study, hydrodynamic focusing of fluids with different conductivities has been used for high through-put cell electroporation at low voltage (<3 V) of continuous direct current (dc) power. Simulation results showed that an input voltage of only 1.5 V could generate an electric field intensity of about 1.17 kV cm(-1) across the cell suspension flow in the squeezed area. The electropermeation of yeast cell was observed, showing a permeabilization percentage up to 70%. PMID: 19757070 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805150 Tue, 15 Sep 2009 23:00:00 +0100 2805150 http://www.medworm.com/index.php?rid=2805151&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757069%26dopt%3DAbstract We report on the development of a microtube electrode array as a neural interface device. To combine the desired properties for the neural interface device, such as low invasiveness with a small needle and a good signal-to-noise ratio in neural recordings, we applied the structure of a glass pipette electrode to each microtube electrode. The device was fabricated as sub-5-mum-diameter out-of-plane silicon dioxide microtube arrays using silicon microneedle templates, which are grown by the selective vapor-liquid-solid method. The microtubes had inner diameters of 1.9-6.4 microm and a length of 25 microm. Impedances ranged from 220 kOmega to 1.55 MOmega, which are less than those for conventional microneedles. In addition, the microtube electrodes had less signal attenuation than conventiona... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805151 Mon, 14 Sep 2009 23:00:00 +0100 2805151 http://www.medworm.com/index.php?rid=2805149&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757071%26dopt%3DAbstract Authors: Tang L, Min J, Lee EC, Kim JS, Lee NY Herein, we introduce the fabrication of polymer micropattern arrays on a chemically inert poly(dimethylsiloxane) (PDMS) surface and employ them for the selective adhesion of cells. To fabricate the micropattern arrays, a mercapto-ester-based photocurable adhesive was coated onto a mercaptosilane-coated PDMS surface and photopolymerized using a photomask to obtain patterned arrays at the microscale level. Robust polymer patterns, 380 microm in diameter, were successfully fabricated onto a PDMS surface, and cells were selectively targeted toward the patterned regions. Next, the performance of the cell adhesion was observed by anchoring cell adhesive linker, an RGD oligopeptide, on the surface of the mercapto-ester-based adhesive-cured layer.... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805149 Mon, 14 Sep 2009 23:00:00 +0100 2805149 http://www.medworm.com/index.php?rid=2805148&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757072%26dopt%3DAbstract This study develops a new microfluidic DNA amplification strategy for executing parallel DNA amplification in the microfluidic gradient polymerase chain reaction (MG-PCR) device. The developed temperature gradient microfluidic system is generated by using an innovative fin design. The device mainly consists of modular thermally conductive copper flake which is attached onto a finned aluminum heat sink with a small fan. In our microfluidic temperature gradient prototype, a non-linear temperature gradient is produced along the gradient direction. On the copper flake of length 45 mm, width 40 mm and thickness 4 mm, the temperature gradient easily spans the range from 97 to 52 degrees C. By making full use of the hot (90-97 degrees C) and cold (60-70 degrees C) regions on the temperature gradi... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805148 Mon, 14 Sep 2009 23:00:00 +0100 2805148 http://www.medworm.com/index.php?rid=2805147&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757073%26dopt%3DAbstract We describe a self-contained fully-enclosed cartridge for lab-on-a-chip applications where sample and reagents can be applied sequentially as is performed in a heterogeneous immunoassay, or nucleic acid extraction. Both the self-contained and fully-enclosed features of the cartridge are sought to ensure its safe use in the field by unskilled staff. Simplicity in cartridge design and operation is obtained via adopting a valveless concept whereby reagents are stored and used in the form of liquid plugs isolated by air spacers around a fluidic loop. Functional components integrated in the loop include a microfluidic chip specific to the target application, a novel peristaltic pump to displace the liquid plugs, and a pair of removable tubing segments where one is used to introduce biological s... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805147 Mon, 14 Sep 2009 23:00:00 +0100 2805147 http://www.medworm.com/index.php?rid=2805146&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757074%26dopt%3DAbstract In this study, we followed an alternative strategy to increase the portion of neurons located at the electrodes by designing a network in confined geometries. Guided settlement and outgrowth of neurons is accomplished by taking control over the adhesive properties of the MEA surface. Using microcontact printing a triangular two-dimensional pattern of the adhesion promoter poly-D-lysine was applied to the MEA offering a meshwork that at the same time provides adhesion points for cell bodies matching the electrode positions and gives frequent branching points for dendrites and axons. Low density neocortical networks cultivated under this condition displayed similar properties to random networks with respect to the cellular morphology but had a threefold higher electrode coverage. Electrical ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2805146 Mon, 14 Sep 2009 23:00:00 +0100 2805146 http://www.medworm.com/index.php?rid=2768101&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19731040%26dopt%3DAbstract Authors: Sabella S, Vecchio G, Pompa PP, Maruccio G, Sanarica L, Torre AD, De Bellis G, Caramenti G, Consolandi C, Severgnini M, Cingolani R, Rinaldi R We show the design, development and assessment of disposable, biocompatible, fully plastic microreactors, which are demonstrated to be highly efficient for genomic analyses, such as amplification of DNA, quantitative analyses in real time, multiplex PCR (both in terms of efficiency and selectivity), as compared to conventional laboratory equipment for PCR. The plastic microreactors can easily be coupled to reusable hardware, enabling heating/cooling processes and, in the case of qPCR applications, the real-time detection of the signal from a suitable fluorescent reporter present in the reaction mixture during the analysis. The low cost ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2768101 Thu, 03 Sep 2009 23:00:00 +0100 2768101 http://www.medworm.com/index.php?rid=2768104&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19731039%26dopt%3DAbstract This study presents a new microfluidic device for bead and cell separation utilizing a combination of T-junction focusing and tilted louver-like structures. For the first time, a microfluidic device is used for continuous separation of amniotic stem cells from amniotic fluids. An experimental separation efficiency as high as 82.8% for amniotic fluid mesenchymal stem cells is achieved. Furthermore, a two-step separation process is performed to improve the separation efficiency to 97.1%. These results are based on characterization experiments that show that this microfluidic chip is capable of separating beads with diameters of 5, 10, 20, and 40 mum by adjusting the volume-flow-rate ratio between the flows in the main and side channels of the T-junction focusing structure. An optimal volume-... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2768104 Wed, 02 Sep 2009 23:00:00 +0100 2768104 http://www.medworm.com/index.php?rid=2713476&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19685189%26dopt%3DAbstract Authors: Keyes J, Junkin M, Wong PK, Vande Geest JP The next generation of tissue engineered constructs (TECs) requires the incorporation of a controllable and optimized microstructure if they are to chemically, mechanically, and biologically mimic tissue function. In order to obtain TECs with optimized microstructures, a combination of spatiotemporally regulated mechanical and biochemical stimuli is necessary during the formation of the construct. While numerous efforts have been made to create functional tissue constructs, there are few techniques available to stimulate TECs in a localized manner. We herein describe the design of a microdevice which can stimulate TECs in a localized, inhomogeneous, and predefined anisotropic fashion using ferromagnetically doped polydimethylsiloxane ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2713476 Thu, 13 Aug 2009 23:00:00 +0100 2713476 http://www.medworm.com/index.php?rid=2700100&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19672717%26dopt%3DAbstract Authors: Chen J, Chu M, Koulajian K, Wu XY, Giacca A, Sun Y A drug-delivery microdevice integrating pH-responsive nano-hydrogel particles functioning as intelligent nano valves is described. The polymeric microdevices are monolithic without requiring peripheral control hardware or additional components for controlling drug-release rates. pH-responsive nanoparticles were synthesized and embedded into a composite membrane. The resulting pH-responsive composite membranes were integrated with PDMS micro reservoirs via a room-temperature transfer bonding technique to form the proof-of-concept microdevices. In vitro release characterization of the microdevices was conducted in which the release rate of Vitamin B(12) (VB(12)) as a model drug increased dramatically when the local pH value was ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2700100 Tue, 11 Aug 2009 23:00:00 +0100 2700100 http://www.medworm.com/index.php?rid=2692255&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19669890%26dopt%3DAbstract Authors: Souza GR, Staquicini FI, Christianson DR, Ozawa MG, Miller JH, Pasqualini R, Arap W The development of improved methods for targeted cell detection is of general interest in many fields of research and drug development. There are a number of well-established techniques for the study and detection of biomarkers expressed in living cells and tissues. Many of them rely on multi-step procedures that might not meet ideal assay requirements for speed, cost, sensitivity, and specificity. Here we report and further validate an approach that enables spontaneous molecular assembly to generate biologically active networks of bacteriophage (phage) assembled with gold (Au) nanoparticles (termed Au-phage nanoshuttles). Here, the nanoshuttles preserve the cell binding and internalization att... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2692255 Mon, 10 Aug 2009 23:00:00 +0100 2692255 http://www.medworm.com/index.php?rid=2675459&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19653101%26dopt%3DAbstract Authors: Ul Haque A, Zuberi M, Diaz-Rivera RE, Marshall Porterfield D Advancements in microfabrication technology have lead to the development of planar micro-pore electroporation technology. This technology has been shown to provide greater control in single cell manipulation, and electroporation which is independent from cell size. In this work we report direct and spatially resolved characterization of electric currents within a planar micropore electroporation biochip to better understand this phenomenon at the cellular level. This work was performed using a two-dimensional (2-D) vibrating probe (VP). Analysis of the spatial patterns of current density yielded a 4th order polynomial profile in the planes parallel to the biochip's surface and a three parameter hyperbolic decay profi... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2675459 Mon, 03 Aug 2009 23:00:00 +0100 2675459 http://www.medworm.com/index.php?rid=2668941&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19649710%26dopt%3DAbstract Authors: Chen CH, Cho SH, Tsai F, Erten A, Lo YH We demonstrate a low-power (<0.1 mW), low-voltage (<10 V(p-p)) on-chip piezoelectrically actuated micro-sorter that can deflect single particles and cells at high-speed. With rhodamine in the stream, switching of flow between channels can be visualized at high actuation frequency (~1.7 kHz). The magnitude of the cell deflection can be precisely controlled by the magnitude and waveform of input voltage. Both simulation and experimental results indicate that the drag force imposed on the suspended particle/cell by the instantaneous fluid displacement can alter the trajectory of the particle/cell of any size, shape, and density of interest in a controlled manner. The open-loop E. Coli cell deflection experiment demonstrates that the s... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2668941 Fri, 31 Jul 2009 23:00:00 +0100 2668941 http://www.medworm.com/index.php?rid=2640458&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19629700%26dopt%3DAbstract Authors: Gimi B, Kwon J, Liu L, Su Y, Nemani K, Trivedi K, Cui Y, Vachha B, Mason R, Hu W, Lee JB With strides in stem cell biology, cell engineering and molecular therapy, the transplantation of cells to produce therapeutic molecules endogenously is an attractive and achievable alternative to the use of exogenous drugs. The encapsulation of such cell transplants in semi-permeable, nanoporous constructs is often required to protect them from immune attack and to prevent their proliferation in the host. However, effective graft immunoisolation has been mostly elusive owing to the absence of a high-throughput method to create precisely controlled, high-aspect-ratio nanopores. To address the clinical need for effective cell encapsulation and immunoisolation, we devised a biocompatible cel... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2640458 Wed, 22 Jul 2009 23:00:00 +0100 2640458 http://www.medworm.com/index.php?rid=2640460&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19629698%26dopt%3DAbstract Authors: Zhang B, Kim MC, Thorsen T, Wang Z Conventional in vitro cell culture that utilizes culture dishes or microtiter plates is labor-intensive and time-consuming, and requires technical expertise and specific facilities to handle cell harvesting, media exchange and cell subculturing procedures. A microfluidic array platform with eight microsieves in each cell culture chamber is presented for continuous cell culture. With the help of the microsieves, uniform cell loading and distribution can be obtained. Within the arrays, cells grown to the point of confluency can be trypsinized and recovered from the device. Cells trapped in the microsieves after trypsinization function to seed the chambers for subsequent on-chip culturing, creating a sustainable platform for multiple cycles. The... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2640460 Mon, 20 Jul 2009 23:00:00 +0100 2640460 http://www.medworm.com/index.php?rid=2640459&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19629699%26dopt%3DAbstract Authors: Johnson PJ, Rosenbluth EM, Nygaard IE, Parikh MK, Hitchcock RW Limitations of standard clinical pressure transducers have hampered our ability to provide reliable measurements of intra-abdominal pressure (IAP) during physical activities. To overcome these limitations, a novel intravaginal transducer (IVT) capable of accurate, reliable, and continuous IAP measurements during normal activity was developed. The design was validated through comparison with standard clinical pressure transducers in both bench top and clinical tests. The IVT demonstrated an improved dynamic response when compared to a standard rectal balloon catheter. Additionally, the radially symmetric design allows for accurate measurement within non-fluid-filled tissue cavities and simple placement within the va... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2640459 Mon, 20 Jul 2009 23:00:00 +0100 2640459 http://www.medworm.com/index.php?rid=2615597&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19609679%26dopt%3DAbstract Authors: Jin CY, Han MH, Lee SS, Choi YH The key issues in the development of a microneedle patch as a tool for transdermal drug delivery are safety and delivery performance in addition to economical production. In this paper, novel fabrication methods for an inexpensive microneedle patch made of biocompatible polymer are reported, along with functional verifications for the fabricated microneedle patch through animal models. We combined the merits of in-line microneedles, i.e., easy and economical production, with the superior performance of two-dimensionally arrayed microneedles. One-dimensionally fabricated microneedles were assembled to make two-dimensionally arrayed patches to attain our goal. First, we fabricated strips with one-dimensionally arrayed microneedles through deep X-r... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2615597 Wed, 15 Jul 2009 23:00:00 +0100 2615597 http://www.medworm.com/index.php?rid=2615596&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19609680%26dopt%3DAbstract Authors: Shan X, Yuan Y, Liu C, Tao X, Sheng Y, Xu F The process of opsonization is the major biological barrier to the injectable polymeric nanoparticles (NPs). Complement protein is one kind of opsonins and it can be activated potentially by the negative charged particles. The fragment C3b generated by complement activation could subsequently induce the opsonization on the NPs surface. The aim of our work was to examine the relationship between the hydrophilic poly(ethylene glycol) (PEG) chain on the surface of NPs and particles longevity in vivo from the biological point of view such as complement activation (C3 cleavage) as well as uptake by macrophages. The studies showed that the introduction of PEG chains led to slightly smaller NPs with lower polydispersities than those prepare... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2615596 Wed, 15 Jul 2009 23:00:00 +0100 2615596 http://www.medworm.com/index.php?rid=2603169&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19597994%26dopt%3DAbstract Authors: Qiu X, Thompson JA, Chen Z, Liu C, Chen D, Ramprasad S, Mauk MG, Ongagna S, Barber C, Abrams WR, Malamud D, Corstjens PL, Bau HH The building blocks for an inexpensive, disposable, luminescence-based microfluidic immunoassay cassette are described, and their integration in a point-of-care diagnostic system is demonstrated. Fluid motion in the cassette is driven by depressing finger-actuated pouches. All reagents needed for the immunoassay can be stored in the cassette in liquid form. Prior to use, the cassette consists of two separate parts. A top storage component contains pouches, sealed storage chambers, a metering chamber, and needle seats. The bottom processing component contains connection needles, a mixing chamber, and a detection chamber with immobilized proteins. Subs... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2603169 Mon, 13 Jul 2009 23:00:00 +0100 2603169 http://www.medworm.com/index.php?rid=2580948&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19578992%26dopt%3DAbstract Authors: Liu X, Sun Y This paper presents the design and microfabrication of a vacuum-based cell holding device for single-cell immobilization and the use of the device in mouse zygote microinjection. The device contains many through-holes, constructed via two-sided glass wet etching and polydimethylsiloxane (PDMS)-glass bonding. Experimental results of mouse zygote immobilization and microinjection demonstrate that the device is effective for rapid cell immobilization and does not produce negative effect on embryonic development. PMID: 19578992 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2580948 Fri, 03 Jul 2009 23:00:00 +0100 2580948 http://www.medworm.com/index.php?rid=2557027&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19562488%26dopt%3DAbstract Authors: Vukasinovic J, Cullen DK, Laplaca MC, Glezer A High density, three-dimensional (3D) cultures present physical similarities to in vivo tissue and are invaluable tools for pre-clinical therapeutic discoveries and development of tissue engineered constructs. Unfortunately, the use of dense cultures is hindered by intra-culture transport limits allowing just a few layer thick cultures for reproducible studies. In order to overcome diffusion limits in intra-culture nutrient and gas availability, a simple scalable microfluidic perfusion platform was developed and validated. A novel perfusion approach maintained laminar flow of nutrients through the culture to meet metabolic need, while removing depleted medium and catabolites. Velocity distributions and 3D flow patterns were measure... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2557027 Fri, 26 Jun 2009 23:00:00 +0100 2557027 http://www.medworm.com/index.php?rid=2525903&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19554452%26dopt%3DAbstract Authors: Park J, Koito H, Li J, Han A This paper presents a circular microfluidic compartmentalized co-culture platform that can be used for central nervous system (CNS) axon myelination research. The microfluidic platform is composed of a soma compartment and an axon/glia compartment connected through arrays of axon-guiding microchannels. Myelin-producing glia, oligodendrocytes (OLs), placed in the axon/glia compartment, interact with only axons but not with neuronal somata confined to the soma compartment, reminiscent to in vivo situation where many axon fibres are myelinated by OLs at distance away from neuronal cell bodies. Primary forebrain neurons from embryonic day 16-18 rats were cultured inside the soma compartment for two weeks to allow them to mature and form extensive axon ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525903 Wed, 24 Jun 2009 23:00:00 +0100 2525903 http://www.medworm.com/index.php?rid=2525905&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19548088%26dopt%3DAbstract Authors: Jeon H, Lee Y, Jin S, Koo S, Lee CS, Yoo JY A microfluidic device to quantify bacterial chemotaxis has been proposed, which generates a linear concentration gradient of chemoattractant in the main channel only by convective and molecular diffusion, and which enables the bacteria to enter the main channel in a single file by hydrodynamic focusing technique. The trajectory of each bacterium in response to the concentration gradient of chemoattractant is photographed by a CCD camera and its velocity is acquired by a simple PTV (Particle Tracking Velocimetry) algorithm. An advantage of this assay is to measure the velocity of a single bacterium and to quantify the degree of chemotaxis by analyzing the frequency of velocities concurrently. Thus, the parameter characterizing the mot... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525905 Mon, 22 Jun 2009 23:00:00 +0100 2525905 http://www.medworm.com/index.php?rid=2525907&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19517239%26dopt%3DAbstract Authors: Baruch L, Benny O, Gilert A, Ukobnik M, Ben Itzhak O, Machluf M In spite of advances in cell microencapsulation technology in the past three decades, this approach still suffers from obstacles associated with its biocompatibility. We hypothesized that encapsulation system, which incorporates polymeric particles releasing anti-inflammatory drug in addition to the encapsulated cells, will result in improved biocompatibility, thus improving therapeutic efficacy. We have developed, optimized and studied a combined microencapsulation system in which Ibuprofen loaded PLGA microspheres (MS) are co-entrapped with cells. The combined system was developed and optimized in terms of Ibuprofen release profile, and the survival and proliferation of the co-encapsulated cells. The biocompatib... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525907 Wed, 10 Jun 2009 23:00:00 +0100 2525907 http://www.medworm.com/index.php?rid=2525909&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19507033%26dopt%3DAbstract Authors: Cosco D, Paolino D, Muzzalupo R, Celia C, Citraro R, Caponio D, Picci N, Fresta M Innovative niosomes made up of alpha,omega-hexadecyl-bis-(1-aza-18-crown-6) (bola), Span 80(R) and cholesterol (2:5:2 molar ratio) are proposed as suitable delivery systems for the administration of 5-fluorouracil (5-FU), an antitumoral compound largely used in the treatment of breast cancer. The bola-niosomes, after sonication procedure, showed mean sizes of ~200 nm and a loading capacity of ~40% with respect to the amount of 5-FU added during the preparation. Similar findings were achieved with PEG-coated bola-niosomes (bola, Span 80(R), cholesterol, DSPE-mPEG2000, 2:5:2:0.1 molar ratio respectively). 5-FU-loaded PEG-coated and uncoated bola-niosomes were tested on MCF-7 and T47D cells. Both bo... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525909 Mon, 08 Jun 2009 23:00:00 +0100 2525909 http://www.medworm.com/index.php?rid=2525911&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19495986%26dopt%3DAbstract Authors: Wang S, Wong Po Foo C, Warrier A, Poo MM, Heilshorn SC, Zhang X Spatial patterning of proteins is a valuable technique for many biological applications and is the prevailing tool for defining microenvironments for cells in culture, a required procedure in developmental biology and tissue engineering research. However, it is still challenging to achieve protein patterns that closely mimic native microenvironments, such as gradient protein distributions with desirable mechanical properties. By combining projection dynamic mask lithography and protein engineering with non-canonical photosensitive amino acids, we demonstrate a simple, scalable strategy to fabricate any user-defined 2D or 3D stable gradient pattern with complex geometries from an artificial extracellular matrix (aE... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525911 Tue, 02 Jun 2009 23:00:00 +0100 2525911 http://www.medworm.com/index.php?rid=2525912&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19488859%26dopt%3DAbstract We present in this paper a new topology of inductively-coupled links based on a monolithic multi-coils receiver. A model is built to characterize the proposed structure using Matlab and is verified employing simulation tools under ADS electromagnetic environment. This topology accounts for the losses associated with the receiver micro-coil including substrate and oxide layers. The geometry of micro-coils significantly desensitizes the link to both angular and side misalignments. A custom fabrication process using 1 micron metal thickness is also presented by which two sets of micro-coils varying in the number of coils are realized. The first set possesses one coil 4 mm of diameter and represents a power efficiency close to 4% while the second set possesses multi-coils with an efficiency of... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525912 Mon, 01 Jun 2009 23:00:00 +0100 2525912 http://www.medworm.com/index.php?rid=2525913&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19484389%26dopt%3DAbstract Authors: Nalayanda DD, Puleo C, Fulton WB, Sharpe LM, Wang TH, Abdullah F In an effort to improve the physiologic relevance of existing in vitro models for alveolar cells, we present a microfluidic platform which provides an air-interface in a dynamic system combining microfluidic and suspended membrane culture systems. Such a system provides the ability to manipulate multiple parameters on a single platform along with ease in cell seeding and manipulation. The current study presents a comparison of the efficacy of the hybrid system with conventional platforms using assays analyzing the maintenance of function and integrity of A549 alveolar epithelial cell monolayer cultures. The hybrid system incorporates bio-mimetic nourishment on the basal side of the epithelial cells along with an ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525913 Fri, 29 May 2009 23:00:00 +0100 2525913 http://www.medworm.com/index.php?rid=2525914&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19479379%26dopt%3DAbstract This study develops a driving system for an electrowetting-on-dielectric (EWOD) device comprising a 9 V battery, an ATmega8535 microprocessor, a DC/DC converter, two regulator ICs and a switch circuit. The driving system greatly improves the portability of the EWOD device and is capable of generating a square wave with voltages ranging from 50~100 V(pp) and frequencies in the range 1~5 kHz. A series of experimental and numerical investigations are performed to investigate the effect of the conducting electrode geometry on the droplet velocity in the EWOD device. Three different electrode configurations are considered, namely a linear array of square electrodes, a series of interdigitated electrodes having either two or three fingers, and a series of interdigitated electrodes having five or... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525914 Thu, 28 May 2009 23:00:00 +0100 2525914 http://www.medworm.com/index.php?rid=2525916&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19479169%26dopt%3DAbstract Authors: Wang F, Burns MA A microfluidic device was used to characterize PCR in aqueous-in-oil droplets for potential point-of-care applications. Droplets with a volume range of 5-250 nL can be formed on-chip reproducibly, and PCR in the droplets shows amplification efficiencies comparable to benchtop reactions with no evaporation loss. A higher polymerase concentration is required in the reaction droplet while the optimal Magnesium ion concentration is the same for both on-chip and benchtop systems. The optimal hold time is 9 s and 30 s for denaturation and annealing/extension in thermal cycling, respectively. With the optimized cycling parameters, the total reaction time is reduced to half of that required for benchtop PCR. For the droplets containing the same quantity of template DN... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525916 Wed, 27 May 2009 23:00:00 +0100 2525916 http://www.medworm.com/index.php?rid=2525915&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19479170%26dopt%3DAbstract Authors: Chiono V, Vozzi G, Vozzi F, Salvadori C, Dini F, Carlucci F, Arispici M, Burchielli S, Di Scipio F, Geuna S, Fornaro M, Tos P, Nicolino S, Audisio C, Perroteau I, Chiaravalloti A, Domenici C, Giusti P, Ciardelli G Melt-extruded guides for peripheral nerve repair based on poly(epsilon-caprolactone) (PCL) were realised and their physico-chemical properties were evaluated. Preliminarily, PCL cast films were found to support the attachment and proliferation of Neonatal Olfactory Bulb Ensheating Cells (NOBEC). S5Y5 neuroblastoma cells were cultured inside PCL guides in their uncoated form or coated with a non-specific adhesion protein (gelatin) and a specific peptide for nerve regeneration (poly(L-lysine)). Coating increased cell density (gelatin) and/or the cell density rate on su... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525915 Wed, 27 May 2009 23:00:00 +0100 2525915 http://www.medworm.com/index.php?rid=2525917&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19459049%26dopt%3DAbstract Authors: Graham AH, Bowen CR, Taylor J, Robbins J The use of CMOS (Complementary Metal Oxide Semiconductor) integrated circuits to create electrodes for biosensors, implants and drug-discovery has several potential advantages over passive multi-electrode arrays (MEAs). However, unmodified aluminium CMOS electrodes may corrode in a physiological environment. We have investigated a low-cost electrode design based on the modification of CMOS metallisation to produce a nanoporous alumina electrode as an interface to mammalian neuronal cells and corrosion inhibitor. Using NG108-15 mouse neuroblastoma x rat glioma hybrid cells, results show that porous alumina is biocompatible and that the inter-pore distance (pore pitch) of the alumina has no effect on cell vitality. To establish whether po... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525917 Wed, 20 May 2009 23:00:00 +0100 2525917 http://www.medworm.com/index.php?rid=2525918&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19452279%26dopt%3DAbstract Authors: Rosano JM, Tousi N, Scott RC, Krynska B, Rizzo V, Prabhakarpandian B, Pant K, Sundaram S, Kiani MF Existing microfluidic devices, e.g. parallel plate flow chambers, do not accurately depict the geometry of microvascular networks in vivo. We have developed a synthetic microvascular network (SMN) on a polydimethalsiloxane (PDMS) chip that can serve as an in vitro model of the bifurcations, tortuosities, and cross-sectional changes found in microvascular networks in vivo. Microvascular networks from a cremaster muscle were mapped using a modified Geographical Information System, and then used to manufacture the SMNs on a PDMS chip. The networks were cultured with bovine aortic endothelial cells (BAEC), which reached confluency 3-4 days after seeding. Propidium iodide staining ind... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525918 Mon, 18 May 2009 23:00:00 +0100 2525918 http://www.medworm.com/index.php?rid=2525919&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19434498%26dopt%3DAbstract Authors: Lee SS, Yim Y, Ahn KH, Lee SJ The deformability of the red blood cell (RBC), is known to be closely related to microcirculation and diagnosis of specific diseases such as malaria, arterial sclerosis, sepsis, and so on. From the viewpoint of the flow type, conventional methods to measure the cell deformability have exploited simple shear or complex flow field with little focus on extensional flow field. In this paper, we present a new approach to assess cell deformability under the extensional flow field. For this purpose, a hyperbolic converging microchannel was designed, and the cell deformation in the extensional flow region was continuously monitored. It overcomes the limitation of conventional methods by reducing experiment time. As quantified by the degree of deformation,... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525919 Mon, 11 May 2009 23:00:00 +0100 2525919 http://www.medworm.com/index.php?rid=2525920&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19421862%26dopt%3DAbstract Authors: Ramalingam N, Liu HB, Dai CC, Jiang Y, Wang H, Wang Q, M Hui K, Gong HQ A major challenge for the lab-on-a-chip (LOC) community is to develop point-of-care diagnostic chips that do not use instruments. Such instruments include pumping or liquid handling devices for distribution of patient's nucleic-acid test sample among an array of reactors and microvalves or mechanical parts to seal these reactors. In this paper, we report the development of a primer pair pre-loaded PCR array chip, in which the loading of the PCR mixture into an array of reactors and subsequent sealing of the reactors were realized by a novel capillary-based microfluidics with a manual two-step pipetting operations. The chip is capable of performing simultaneous (parallel) analyses of multiple gene targets a... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525920 Wed, 06 May 2009 23:00:00 +0100 2525920 http://www.medworm.com/index.php?rid=2525922&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19415498%26dopt%3DAbstract Authors: Shafiee H, Caldwell JL, Sano MB, Davalos RV Dielectrophoresis (DEP) has become a promising technique to separate and identify cells and microparticles suspended in a medium based on their size or electrical properties. Presented herein is a new technique to provide the non-uniform electric field required for DEP that does not require electrodes to contact the sample fluid. In our method, electrodes are capacitively-coupled to a fluidic channel through dielectric barriers; the application of a high-frequency electric field to these electrodes then induces an electric field in the channel. This technique combines the cell manipulation abilities of traditional DEP with the ease of fabrication found in insulator-based technologies. A microfluidic device was fabricated based on thi... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525922 Mon, 04 May 2009 23:00:00 +0100 2525922 http://www.medworm.com/index.php?rid=2525921&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19415499%26dopt%3DAbstract Authors: Ghubade A, Mandal S, Chaudhury R, Singh RK, Bhattacharya S The detection and counting of micro particles having sizes comparable to biological entities can provide a tremendous impetus to rapid diagnostics and clinical applications. MEMS technology has already been used in capture and detection of such micron size entities in miniscule concentrations. For this purpose a concentration step is normally added prior to the detection process. A variety of methodologies are used for quantization of such micron size particles/entities including change in permittivity, medium impedance, magnetic permeability and other means. Although optical studies have been extensively performed prior to this, it has not been used for quantization of the micro particles. We have designed, developed ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525921 Mon, 04 May 2009 23:00:00 +0100 2525921 http://www.medworm.com/index.php?rid=2525923&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19399625%26dopt%3DAbstract Authors: Han SI, Han KH, Frazier AB, Ferrance JP, Landers JP This paper presents an automated micro-SPE device for DNA extraction using monolithically integrated high-pressure microvalves. The automated micro-SPE device was fabricated through glass-to-glass thermal bonding and microfluidic system interface technologies. To increase the DNA extraction efficiency, silica beads were packed in the extraction microchannel involving two weir structures. Experimental results show that the DNA extraction efficiency using the automated micro-SPE device containing bare silica beads was 75.87% in the first 8 mul of solution eluted by automated SPE procedure. In addition, the reproducibility of the DNA extraction was evaluated by ten successive measurements. Genomic DNA extracted from human WBCs h... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525923 Mon, 27 Apr 2009 23:00:00 +0100 2525923 http://www.medworm.com/index.php?rid=2525925&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19396548%26dopt%3DAbstract Authors: Lo R, Li PY, Saati S, Agrawal RN, Humayun MS, Meng E An implantable manually-actuated drug delivery device, consisting of a refillable drug reservoir, flexible cannula, check valve, and suture tabs, was investigated as a new approach for delivering pharmaceuticals to treat chronic ocular diseases. Devices are fabricated by molding and bonding three structured layers of polydimethylsiloxane. A 30 gauge non-coring needle was used to refill the reservoir; this size maximized the number of repeated refills while minimizing damage to the reservoir. The check valve cracking pressure was 76 +/- 8.5 mmHg (mean +/- SE, n = 4); the valve sustained > 2000 mmHg of reverse pressure without leakage. Constant delivery at 1.57 +/- 0.2 microL/sec and 0.61 +/- 0.2 microL/sec (mean +/- SE, n ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525925 Fri, 24 Apr 2009 23:00:00 +0100 2525925 http://www.medworm.com/index.php?rid=2525926&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19387837%26dopt%3DAbstract Authors: Tan SJ, Yobas L, Lee GY, Ong CN, Lim CT Cancer metastasis is the main attribute to cancer-related deaths. Furthermore, clinical reports have shown a strong correlation between the disease development and number of circulating tumor cells (CTCs) in the peripheral blood of cancer patients. Here, we present a label-free microdevice capable of isolating cancer cells from whole blood via their distinctively different physical properties such as deformability and size. The isolation efficiency is at least 80% for tests performed on breast and colon cancer cells. Viable isolated cells are also obtained which may give further insights to the understanding of the metastatic process. Contrasting with conventional biochemical techniques, the uniqueness of this microdevice lies in the mec... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525926 Wed, 22 Apr 2009 23:00:00 +0100 2525926 http://www.medworm.com/index.php?rid=2525927&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19387836%26dopt%3DAbstract Authors: Pal S, Kim MJ, Tak YK, Kwon HT, Song JM This paper reports the design, fabrication and testing of a microchip wherein interdigitated microelectrode arrays (IMEA) were integrated with bipolar semiconductor photodiode array (PDA) chip to fabricate a highly compact embodiment for on-chip handling of solutions and electrochemiluminescence (ECL) detection. A 12 x 12 micro array of photodiodes, each coupled with an interdigitated microelectrode array (IMEA), an array of current amplifiers, and a photodiode element-addressing circuit were integrated into a single 2 x 2 cm(2) IC chip. Each photodiode had dimensions of 300 x 300 mum(2) and the photodiode-to-photodiode distance was 100 mum. The chip was successfully applied to the on-chip quantification of electro-chemiluminescing probe... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525927 Tue, 21 Apr 2009 23:00:00 +0100 2525927 http://www.medworm.com/index.php?rid=2525929&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19381815%26dopt%3DAbstract We present a simple and high-throughput microfluidic system for diffusion-based monolayer yeast cell culture monitoring. Yeast cells are patterned into the micro-cavity array with a suitable height (4 mum) that keeps the cells fixed in monolayer during the cell division. Different sizes of cavities and different repeating times of injection were tested in order to realize as many single-cell/cavity as possible. Single-cell/cavity has been achieved in about 40% of 100 parallel cavities. As a demonstration, we apply this technology to investigate budding yeast and fission yeast cultures and show that it permits single-cell resolution over many cellular generations. Our results show that the technique provides an easy way to study the phenotype of single yeast cell cycle or cell-cell communic... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525929 Mon, 20 Apr 2009 23:00:00 +0100 2525929 http://www.medworm.com/index.php?rid=2525928&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19381816%26dopt%3DAbstract Authors: Zhang SX, Gao J, Buchholz TA, Wang Z, Salehpour MR, Drezek RA, Yu TK Gold nanoparticles can enhance the biological effective dose of radiation delivered to tumors, but few data exist to quantify this effect. The purpose of this project was to build a Monte Carlo simulation model to study the degree of dose enhancement achievable with gold nanoparticles. A Monte Carlo simulation model was first built using Geant4 code. An Ir-192 brachytherapy source in a water phantom was simulated and the calculation model was first validated against previously published data. We then introduced up to 10(13) gold nanospheres per cm(3) into the water phantom and examined their dose enhancement effect. We compared this enhancement against a gold-water mixture model that has been previously used ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525928 Mon, 20 Apr 2009 23:00:00 +0100 2525928 http://www.medworm.com/index.php?rid=2525931&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19370417%26dopt%3DAbstract This study reports a new microfluidic cell culture platform for real-time, in vitro microscopic observation and evaluation of cellular functions. Microheaters, a micro temperature sensor, and micropumps are integrated into the system to achieve a self-contained, perfusion-based, cell culture microenvironment. The key feature of the platform includes a unique, ultra-thin, culture chamber with a depth of 180 mum, allowing for real-time, high-resolution cellular imaging by combining bright field and fluorescent optics to visualize nanoparticle-cell/organelle interactions. The cell plating, culturing, harvesting and replenishing processes are performed automatically. The developed platform also enables drug screening and real-time, in situ investigation of the cellular and sub-cellular deliver... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525931 Wed, 15 Apr 2009 23:00:00 +0100 2525931 http://www.medworm.com/index.php?rid=2525930&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19370418%26dopt%3DAbstract In this study, a new microfluidic system is presented which can culture and differentiate MSCs in situ. It is composed of several components, including stem cell culture areas, micropumps, microgates, seeding reservoirs, waste reservoirs and fluid microchannels; all fabricated by using micro-electro-mechanical-systems (MEMS) technology. The developed automated system allows for the long-term culture and differentiation of MSCs. Three methods, including Oil Red O staining for adipogenic cells, alkaline phosphatase staining and immunofluorescence staining are used to assess the differentiation of MSCs. Experimental results clearly demonstrate that the MSCs can be cultured for proliferation and different types of differentiation are possible in this microfluidic system, which can maintain a s... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525930 Wed, 15 Apr 2009 23:00:00 +0100 2525930 http://www.medworm.com/index.php?rid=2525937&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19365730%26dopt%3DAbstract Authors: Lee LM, Cui X, Yang C The optofluidic microscope (OFM) is a lensless, low-cost and highly compact on-chip device that can enable high-resolution microscopy imaging. The OFM performs imaging by flowing/scanning the target objects across a slanted hole array; by measuring the time-varying light transmission changes through the holes, we can then render images of the target objects at a resolution that is comparable to the holes' size. This paper reports the adaptation of the OFM for imaging Giardia lamblia trophozoites and cysts, a disease-causing parasite species that is commonly found in poor-quality water sources. We also describe our study of the impact of pressure-based flow and DC electrokinetic-based flow in controlling the flow motion of Giardia cysts-rotation-free trans... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525937 Mon, 13 Apr 2009 23:00:00 +0100 2525937 http://www.medworm.com/index.php?rid=2525935&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19365731%26dopt%3DAbstract Authors: Clow A, Gaynor P, Oback B Automated lab on chip systems offer increased throughput and reproducibility, but the implementation of microelectrodes presently relies on miniaturisation of parallel plate electrodes that are time consuming and costly to fabricate. Electric field modelling of open electrofusion chambers suggested that widely spaced (>/=2 mm) coplanar film electrodes should result in similar cell fusion rates as parallel plate electrodes provided the cell positioning was roughly midway between the electrodes. This hypothesis was investigated by electrofusion trials of bovine oocyte-donor cell couplets used in nuclear transfer (NT) cloning. Comparative experiments with reference parallel plate electrodes were conducted as controls. Coplanar fusion rates >/= 90% ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525935 Mon, 13 Apr 2009 23:00:00 +0100 2525935 http://www.medworm.com/index.php?rid=2525934&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19365732%26dopt%3DAbstract Authors: Wang GJ, Lin YC, Li CW, Hsueh CC, Hsu SH, Hung HS In this research, two simple fabrication methods to fabricate orderly nanostructured PLGA scaffolds using anodic aluminum oxide (AAO) template were conducted. In the vacuum air-extraction approach, the PLGA solution was cast on an AAO template first. The vacuum air-extraction process was then applied to suck the semi-congealed PLGA into the nanopores of the AAO template to form a bamboo sprouts array of PLGA. The surface roughness of the nanostructured scaffolds, ranging from 20 nm to 76 nm, can be controlled by the sucking time of the vacuum air-extraction process. In the replica molding approach, the PLGA solution was cast on the orderly scraggy barrier-layer surface of an AAO membrane to fabricate a PLGA scaffold of concave ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525934 Mon, 13 Apr 2009 23:00:00 +0100 2525934 http://www.medworm.com/index.php?rid=2525932&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19365733%26dopt%3DAbstract Authors: Chu M, Kudo H, Shirai T, Miyajima K, Saito H, Morimoto N, Yano K, Iwasaki Y, Akiyoshi K, Mitsubayashi K A flexible biosensor using a phospholipid polymer to immobilization of glucose oxidase (GOD) was fabricated and tested. At first, an enzyme membrane formed by immobilizing GOD onto a porous polytetrafluoroethylene (PTFE) membrane using the phospholipid polymer (2-methacryloyloxyethyl phosphorylcholine (MPC) copolymerized with 2-ethylhexylmethacrylate (EHMA) : PMEH) was evaluated. According to the result of amperometric measurement, average density of GOD to be immobilized was optimized to 38.9 units cm(-2). Temperature and pH dependences were also investigated. Then, a flexible glucose sensor was fabricated by immobilizing GOD onto a flexible hydrogen peroxide electrode usin... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525932 Mon, 13 Apr 2009 23:00:00 +0100 2525932 http://www.medworm.com/index.php?rid=2525944&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19353271%26dopt%3DAbstract Authors: Foley CP, Nishimura N, Neeves KB, Schaffer CB, Olbricht WL Convection enhanced delivery (CED) can improve the spatial distribution of drugs delivered directly to the brain. In CED, drugs are infused locally into tissue through a needle or catheter inserted into brain parenchyma. Transport of the infused material is dominated by convection, which enhances drug penetration into tissue compared with diffusion mediated delivery. We have fabricated and characterized an implantable microfluidic device for chronic convection enhanced delivery protocols. The device consists of a flexible parylene-C microfluidic channel that is supported during its insertion into tissue by a biodegradable poly(DL-lactide-co-glycolide) scaffold. The scaffold is designed to enable tissue penetration and ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525944 Tue, 07 Apr 2009 23:00:00 +0100 2525944 http://www.medworm.com/index.php?rid=2525942&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19353272%26dopt%3DAbstract This study demonstrates the feasibility of the integration of LSPR-based biosensing with microfluidic technologies, resulting in a low-cost and portable biosensor candidate compared to the larger and more expensive commercial instruments. PMID: 19353272 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525942 Tue, 07 Apr 2009 23:00:00 +0100 2525942 http://www.medworm.com/index.php?rid=2525940&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19353273%26dopt%3DAbstract We present the overall design, operating principle and construction of the device, and experimental results showing the volume transport rate as a function of the strength of the applied electric field. The concentration profile vs. time, the power consumption, and ejection efficiency are also investigated. To demonstrate the medical utility of the device we also characterize the in-vitro release of vasopressin. PMID: 19353273 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525940 Tue, 07 Apr 2009 23:00:00 +0100 2525940 http://www.medworm.com/index.php?rid=2525946&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19347587%26dopt%3DAbstract Authors: Häfeli UO, Mokhtari A, Liepmann D, Stoeber B A microfabrication process for miniature syringes is described. The MEMS syringes consist of a silicon plate with an array of hollow out-of-plane needles and a flexible poly-dimethylsiloxane (PDMS) reservoir attached to the back of the plate. The PDMS reservoir can be filled with a drug solution or microparticle suspension which is delivered into the skin simply by the pressure of a finger pushing on the miniature syringe. The efficiency of such a syringe for delivering a suspension of microparticles into skin tissue and a radiolabelled protein (albumin) solution into live mice is reported. Such microneedle devices could be used for the intradermal delivery of vaccination agents or for the systemic delivery of highly effective ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525946 Fri, 03 Apr 2009 23:00:00 +0100 2525946 http://www.medworm.com/index.php?rid=2525948&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19343497%26dopt%3DAbstract Authors: Haessler U, Kalinin Y, Swartz MA, Wu M The current state-of-art in 3D microfluidic chemotaxis device (muFCD) is limited by the inherent coupling of the fluid flow and chemical concentration gradients. Here, we present an agarose-based 3D muFCD that decouples these two important parameters, in that the flow control channels are separated from the cell compartment by an agarose gel wall. This decoupling is enabled by the transport property of the agarose gel, which-in contrast to the conventional microfabrication material such as polydimethylsiloxane (PDMS)-provides an adequate physical barrier for convective fluid flow while at the same time readily allowing protein diffusion. We demonstrate that in this device, a gradient can be pre-established in an agarose layer above the ce... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2525948 Thu, 02 Apr 2009 23:00:00 +0100 2525948 http://www.medworm.com/index.php?rid=2300800&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19326217%26dopt%3DAbstract Authors: Maeda Y, Yoshida R Thermosensitive poly(N-isopropylacrylamide) gels with highly-ordered honeycome surface and inverse opal structure were successfully fabricated by several microfabrication methods using closely packed silica beads as a template. The gels are able to reversibly change the shapes and sizes of the pores with swelling-deswelling by temperature changes. In particular, regular buckling was induced due to compression with swelling. Such a thermoregulation of surface topography might be useful for design of functional surfaces with tunable physical properties. PMID: 19326217 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2300800 Fri, 27 Mar 2009 04:00:00 +0100 2300800 http://www.medworm.com/index.php?rid=2300804&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19319683%26dopt%3DAbstract This study establishes PDMS-encapsulated LiNc-BuO as a promising choice of probe for clinical EPR oximetry. PMID: 19319683 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2300804 Thu, 26 Mar 2009 04:00:00 +0100 2300804 http://www.medworm.com/index.php?rid=2300802&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19319684%26dopt%3DAbstract Authors: Lam L, Sakakihara S, Ishizuka K, Takeuchi S, Arata HF, Fujita H, Noji H PMID: 19319684 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2300802 Thu, 26 Mar 2009 04:00:00 +0100 2300802 http://www.medworm.com/index.php?rid=2275168&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19294514%26dopt%3DAbstract In this study, ECM-containing devices shaped as Partial Ossicular Replacement Prostheses (PORPs) were fabricated reproducing the current synthetic models. Biological PORPs were obtained from human decellularized cortical bone allografts by computer numerically controlled ultraprecision micromilling. Moreover, porous PORP-like scaffolds were produced and cultured with osteoinduced human mesenchymal stromal cells to generate in vitro bone ECM within the scaffold porosity (biohybrid PORPs). The acoustic responses of such devices were investigated and compared to those of commercial prostheses. Results showed that biological PORPs transmit mechanical signals with appropriate frequencies, amplitudes, and with early extinction time. Although signal transmission in biohybrid PORPs showed insuffic... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2275168 Thu, 19 Mar 2009 04:00:00 +0100 2275168 http://www.medworm.com/index.php?rid=2275170&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19291408%26dopt%3DAbstract Authors: de Asis ED, Nguyen-Vu TD, Arumugam PU, Chen H, Cassell AM, Andrews RJ, Yang CY, Li J Long-term neuroprostheses for functional electrical stimulation must efficiently stimulate tissue without electrolyzing water and raising the extracellular pH to toxic levels. Comparison of the stimulation efficiency of tungsten wire electrodes (W wires), platinum microelectrode arrays (PtMEA), as-grown vertically aligned carbon nanofiber microbrush arrays (VACNF MBAs), and polypyrrole coated (PPy-coated) VACNF MBAs in eliciting field potentials in the hippocampus slice indicates that, at low stimulating voltages that preclude the electrolysis of water, only the PPy-coated VACNF MBA is able to stimulate the CA3 to CA1 pathway. Unlike the W wires, PtMEA, as-grown VACNF MBA, and the PPy-coated V... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2275170 Tue, 17 Mar 2009 04:00:00 +0100 2275170 http://www.medworm.com/index.php?rid=2275169&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19291409%26dopt%3DAbstract Authors: Meenakshisundaram G, Eteshola E, Pandian RP, Bratasz A, Lee SC, Kuppusamy P Lithium octa-n-butoxynaphthalocyanine (LiNc-BuO) is a promising probe for biological electron paramagnetic resonance (EPR) oximetry and is being developed for clinical use. However, clinical applicability of LiNc-BuO may be hindered by potential limitations associated with biocompatibility, biodegradation, and migration of individual crystals in tissue. To overcome these limitations, we have encapsulated LiNc-BuO crystals in polydimethyl siloxane (PDMS), an oxygen-permeable and bioinert polymer, to fabricate conveniently implantable and retrievable oxygen-sensing chips. Encapsulation was performed by a simple cast-molding process, giving appreciable control over size, shape, thickness and spin density ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2275169 Tue, 17 Mar 2009 04:00:00 +0100 2275169 http://www.medworm.com/index.php?rid=2275171&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19288199%26dopt%3DAbstract Authors: Zhang X, Xie Y, Koh CG, James Lee L A novel method of making microcapsules in a macrocapsule is demonstrated as a 3-D culture system in this article. Mouse embryonic stem (mES) cells as model cells were used in the 3-D culture space, and the cell viability and histological observation were conducted. Furthermore, Oct4 gene expression was evaluated for the undifferentiated status of mES cells in this 3-D model. The results showed that mES cells can grow in this 3-D model and retain their normal viability and morphology. This 3-D model allows mES cells to stay in the undifferentiated state better than 2-D culture systems. This work demonstrates a new 3-D tissue model which can provide an in vivo like microenvironment for non-differentiated mES cells with good immunoisolation. Th... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2275171 Sat, 14 Mar 2009 04:00:00 +0100 2275171 http://www.medworm.com/index.php?rid=2242562&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19259825%26dopt%3DAbstract In this study we measure DNA melting temperature from two plasmid fragments. The effects of flow velocity and ramp-rate are investigated, and measured melting curves are compared to those acquired from a commercially available PCR thermocycler. PMID: 19259825 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2242562 Wed, 04 Mar 2009 05:00:00 +0100 2242562 http://www.medworm.com/index.php?rid=2224157&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19242806%26dopt%3DAbstract In this study, we investigated the effects of the diameter of microfibers on the orientation (angle between cells' major axis and the substrate fiber long axis) of adhered cells. For this purpose, mouse fibroblast L929 cells were cultured on the surface of PLGA fibers of defined diameters ranging from 10 to 242 mum, and their adhesion and alignment was quantitatively analyzed. It was found that the mean orientation of cells and the spatial variation of cell alignment angle directly related to the microfiber diameter. Cells that were cultured on microfibrous scaffolds oriented along the long axis of the microfiber and the orientation increased as the fiber diameter decreased. For the fiber diameter of 10 mum, the mean orientation was 3.0 +/- 0.2 degrees (mean +/- SE), whereas for a diameter... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2224157 Thu, 26 Feb 2009 05:00:00 +0100 2224157 http://www.medworm.com/index.php?rid=2218233&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19241172%26dopt%3DAbstract Authors: Vente MA, Nijsen JF, de Roos R, van Steenbergen MJ, Kaaijk CN, Koster-Ammerlaan MJ, de Leege PF, Hennink WE, van Het Schip AD, Krijger GC Poly(L-lactic acid) microspheres loaded with holmium-166 acetylacetonate ((166)Ho-PLLA-MS) are a novel microdevice for intra-arterial radioembolization in patients with unresectable liver malignancies. The neutron activation in a nuclear reactor, in particular the gamma heating, damages the (166)Ho-PLLA-MS. The degree of damage is dependent on the irradiation characteristics and irradiation time in a particular reactor facility. The aim of this study was to standardize and objectively validate the activation procedure in a particular reactor. The methods included light- and scanning electron microscopy (SEM), particle size analysis, differen... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2218233 Wed, 25 Feb 2009 05:00:00 +0100 2218233 http://www.medworm.com/index.php?rid=2218234&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19238547%26dopt%3DAbstract Authors: Steinert CP, Kalkandjiev K, Zengerle R, Koltay P The standard TopSpot(R) technology has been successfully used in the recent years for the highly parallel nanoliter dispensing of bio-chemical substances for microarray printing. It is based on a pneumatically actuated printhead which enables non-contact microarray fabrication at a pitch of typically 500 microm. This paper reports on a new and improved way of operating the printheads termed TopSpot(R) Vario technology, using an incompressible material between the piezo actuator and the dispensing medium. The advantage of the incompressible medium is the direct relation between the displacement amplitude and the ejected liquid volume. Earlier reports stated that the filling of the printheads is a key issue. In this paper we repor... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2218234 Tue, 24 Feb 2009 05:00:00 +0100 2218234 http://www.medworm.com/index.php?rid=2184559&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19212816%26dopt%3DAbstract Authors: Sung JH, Shuler ML Formation of air bubbles is a serious obstacle to a successful operation of a long-term microfluidic systems using cell culture. We developed a microscale bubble trap that can be integrated with a microfluidic device to prevent air bubbles from entering the device. It consists of two PDMS (polydimethyldisiloxane) layers, a top layer providing barriers for blocking bubbles and a bottom layer providing alternative fluidic paths. Rather than relying solely on the buoyancy of air bubbles, bubbles are physically trapped and prevented from entering a microfluidic device. Two different modes of a bubble trap were fabricated, an independent module that is connected to the main microfluidic system by tubes, and a bubble trap integrated with a main system. The bubble ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2184559 Thu, 12 Feb 2009 05:00:00 +0100 2184559 http://www.medworm.com/index.php?rid=2184558&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19212817%26dopt%3DAbstract We describe the fabrication of three-dimensional tissue constructs using a magnetic force-based tissue engineering technique, in which cellular organization is controlled by magnetic force. Target cells were labeled with magnetite cationic liposomes (MCLs) so that the MCL-labeled cells could be manipulated by applying a magnetic field. Line patterning of human umbilical vein endothelial cells (HUVECs) labeled with MCLs was successfully created on monolayer cells or skin tissues using a magnetic concentrator device. Multilayered cell sheets were also inducible on a culture surface by accumulating MCL-labeled cells under a uniform magnetic force. Based on these results, we attempted to construct a complex multilayered myoblast C2C12 cell sheet. Here, patterned HUVECs were embedded by alterna... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2184558 Thu, 12 Feb 2009 05:00:00 +0100 2184558 http://www.medworm.com/index.php?rid=2184560&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205887%26dopt%3DAbstract Authors: Kang XJ, Chen LQ, Wang Y, Zhang YY, Gu ZZ A mini-column packed with 1 mg electrospun polystyrene nanofibers (about 200 approximately 400 nm in diameter) was designed for simple, fast extraction of drugs, diazepam and its major metabolite, N-desmethyldiazepam for the analysis of them in human and dog plasma. Ttrezodone was selected as internal standard. The drugs adsorbed on the solid phase could be desorpted with 50 mul of the methanol and then monitored by liquid chromatography coupled to an ultraviolet detector. Parameters influencing the extraction efficiency such as fiber packing amount, eluted solvent, and pH of the sample were decided. The time for the pretreatment of 0.5 ml plasma sample was less than 10 min. The detection limits of diazepam and N-desmethyldiazepam in p... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2184560 Tue, 10 Feb 2009 05:00:00 +0100 2184560 http://www.medworm.com/index.php?rid=2135242&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19169824%26dopt%3DAbstract Authors: James CD, Moorman MW, Carson BD, Branda CS, Lantz JW, Manginell RP, Martino A, Singh AK We have developed a microfluidic platform for real-time imaging of host-pathogen interactions and cellular signaling events. Host cells are immobilized in a controlled environment for optical interrogation of the kinetics and stochasticity of immune response to pathogenic challenges. Here, we have quantitatively measured activation of the toll-like receptor 4 (TLR4) pathway in RAW264.7 murine macrophage-like cells. This was achieved by measuring the cytoplasm-to-nucleus translocation kinetics of a green fluorescent protein fusion construct to the NF-kappaB transcription factor subunit RelA (GFP-RelA). Translocation kinetics in response to live bacteria and purified lipopolysaccharide (LPS) ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2135242 Sat, 24 Jan 2009 05:00:00 +0100 2135242 http://www.medworm.com/index.php?rid=2135241&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19169825%26dopt%3DAbstract Authors: Hartung R, Brösing A, Sczcepankiewicz G, Liebert U, Häfner N, Dürst M, Felbel J, Lassner D, Köhler JM We have established a fast PCR-based micro flow-through process consisting of a helical constructed tube reactor. By this approach we can detect transcripts of measles and human papilloma virus (HPV) by continuous flow allowing for reverse transcription (RT) and amplification of cDNA. The micro reaction system consisted of two columnar reactors for thermostating the different reaction zones of the RT process and the amplification. The PCR reactor was built by asymmetric heating sections thus realizing different residence times and optimal conditions for denaturation, annealing and elongation. The system concept is based on low electrical power consumption (... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2135241 Sat, 24 Jan 2009 05:00:00 +0100 2135241 http://www.medworm.com/index.php?rid=2135240&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19169826%26dopt%3DAbstract Authors: Elman NM, Ho Duc HL, Cima MJ We introduce the first implantable drug delivery system based on MEMS (Micro-Electro-Mechanical-Systems) technology specifically designed as a platform for treatment in ambulatory emergency care. The device is named IRD(3) (implantable rapid drug delivery device) and allows rapid delivery of drugs. Vasopressin was used as a model drug for in vitro tests as it is a commonly used drug for cardiac resuscitation. Experimental results reveal that the IRD(3) provides an effective method for rapid delivery without significant drug degradation. Several medical uses and delivery modalities for IRD(3) are proposed. PMID: 19169826 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2135240 Sat, 24 Jan 2009 05:00:00 +0100 2135240 http://www.medworm.com/index.php?rid=2135239&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19169827%26dopt%3DAbstract We present an overview of progress towards single-chip RFID solutions. To date heterogeneous integration has been appropriate for non-biological systems. However, for in-vivo sensors and even drug delivery systems, a small form factor is required. We discuss fundamental limits on the size of the form factor, the effect of the antenna, and propose a unified single-chip RFID solution appropriate for a broad range of biomedical in-vivo device applications, both current and future. Fundamental issues regarding the possibility of single cell RF radios to interface with biological function are discussed. PMID: 19169827 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2135239 Sat, 24 Jan 2009 05:00:00 +0100 2135239 http://www.medworm.com/index.php?rid=2129870&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19165603%26dopt%3DAbstract Authors: Rahman AR, Guiseppi-Elie A The use of microlithographically fabricated Microdisc Electrode Arrays (MDEAs) in the development of implantable voltammetric biosensors necessitates design criteria that balances the overall footprint of the device with the advantages to be derived from large separation distances between non-interacting microdisc elements. Using the dynamic electroanalytical techniques of Multiple Scan Rate Cyclic Voltammetry (MSRCV) experiments with finite element simulations and Electrochemical Impedance Spectroscopy with equivalent circuit modeling, three unique MDEA designs; MDEA 050 (r = 25 mum, 5,184 discs), MDEA 100 (r = 50 mum, 1,296 discs) and MDEA 250 (r = 125 mum, 207 discs) of constant critical dimensions (center-to-center d/r = 4) and area (A = 0.1 cm(2... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2129870 Fri, 23 Jan 2009 05:00:00 +0100 2129870 http://www.medworm.com/index.php?rid=2105340&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19142733%26dopt%3DAbstract This study provides information on the potential for using fluorescence-based screening of functional peptides on a glass array format. PMID: 19142733 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2105340 Wed, 14 Jan 2009 05:00:00 +0100 2105340 http://www.medworm.com/index.php?rid=2105339&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19142734%26dopt%3DAbstract Authors: Zhu Y, Warrick JW, Haubert K, Beebe DJ, Yin J The plaque assay has long served as the "gold standard" to measure virus infectivity and test antiviral drugs, but the assay is labor-intensive, lacks sensitivity, uses excessive reagents, and is hard to automate. Recent modification of the assay to exploit flow-enhanced virus spread with quantitative imaging has increased its sensitivity. Here we performed flow-enhanced infection assays in microscale channels, employing passive fluid pumping to inoculate cell monolayers with virus and drive infection spread. Our test of an antiviral drug (5-fluorouracil) against vesicular stomatitis virus infections of BHK cell monolayers yielded a two-fold improvement in sensitivity, relative to the standard assay based on plaque counting. The re... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2105339 Wed, 14 Jan 2009 05:00:00 +0100 2105339 http://www.medworm.com/index.php?rid=2090661&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130238%26dopt%3DAbstract We report on a simple method for self loading and culture of mammalian cells in microfluidic multi-chambers for high throughput screening. The device was obtained by using one layer soft lithography with polydimethylsiloxane (PDMS) and thermal bonding on a glass slide. Self loading of cell suspension could be possible after degassing of the PDMS device for 30 min. Both cell loading efficiency and cell proliferation behaviors have been analyzed with triangle chambers of different sizes, all connected to the main flow channels with small entrances. We found that the number of cells loaded into the micro-chamber increased with the side length of the triangle, showing well size dependence and that self loading at a single cell level was possible for small chambers. For large chambers, the cell... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090661 Fri, 09 Jan 2009 05:00:00 +0100 2090661 http://www.medworm.com/index.php?rid=2090660&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130239%26dopt%3DAbstract Authors: Kulinski MD, Mahalanabis M, Gillers S, Zhang JY, Singh S, Klapperich CM Silica impregnated polymer monolithic columns may provide a simple method for lysing and extracting DNA from bacteria inside of microfluidic chips. Here we use Escherichia coli as a test organism for a point of care thermoplastic microfluidic module designed to take in a urine sample, mix it with lysis buffer, and perform a hybrid chemical/mechanical lysis and solid phase extraction of nucleic acids from the sample. To demonstrate proof-of-concept, we doped human hematuric urine samples with E. coli at concentrations ranging from 10(1)-10(5) colony-forming units/mL (CFU/mL) to simulate patient samples. We then performed on-chip lysis and DNA extraction. The bacterial DNA was amplified using real-time PCR d... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090660 Fri, 09 Jan 2009 05:00:00 +0100 2090660 http://www.medworm.com/index.php?rid=2090659&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130240%26dopt%3DAbstract Authors: Darain F, Gan KL, Tjin SC A simple microfluidic immunoassay card was developed based on polystyrene (PS) substrate for the detection of horse IgG, an inexpensive model analyte using fluorescence microscope. The primary antibody was captured onto the PS based on covalent bonding via a self-assembled monolayer (SAM) of thiol to pattern the surface chemistry on a gold-coated PS. The immunosensor chip layers were fabricated from sheets by CO(2) laser ablation. The functionalized PS surfaces after each step were characterized by contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). After the antibody-antigen interaction as a sandwich immunoassay with a fluorescein isothiocyanate (FITC)-conjugated secondary antibody, the intensity of f... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090659 Fri, 09 Jan 2009 05:00:00 +0100 2090659 http://www.medworm.com/index.php?rid=2090658&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130241%26dopt%3DAbstract Authors: Hidai H, Jeon H, Hwang DJ, Grigoropoulos CP Development of materials and fabrication techniques lead the growth of three-dimensional cell culture matrices in biomedical engineering. In this work, we present a method for fabricating self-standing fiber scaffolds by two-photon polymerization induced by a femtosecond laser. The aligned fibers are 330 mum long with a diameter of 6-9 mum. Depending on the pitch of the aligned fibers, various cell morphologies are distinguished via three-dimensional images. Furthermore, the morphologies of fibroblast cells (NIH-3T3) and epithelial cells (MDCK) on the fiber scaffolds are studied to show the effect of high curvature (3-4.5 mum radii) on cell morphology. NIH-3T3 cells that contain straight pattern of actin microfilament bundles are ext... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090658 Fri, 09 Jan 2009 05:00:00 +0100 2090658 http://www.medworm.com/index.php?rid=2090657&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130242%26dopt%3DAbstract Authors: Bansal T, Lenhart J, Kim T, Duan C, Maharbiz MM We demonstrate a method which uses simple microfabrication and microfluidics to produce custom, shaped electroporators for the patterned delivery of foreign molecules into developing embryos. We show how these electroporators can be used to 'draw' two-dimensional patterns of tracer molecules, DNA and mRNA into the yolk and cells of zebrafish embryos (Danio rerio) at different stages of development. We demonstrate the successful delivery of patterns of Trypan Blue (normal dye), Texas Red (fluorescent dye), GFP-expressing DNA plasmids and GFP expressing mRNA constructs into both chorionated and dechorionated embryos. Both DNA and mRNA were expressed in the desired patterns subsequent to delivery. Square pulses of 10-20 V (0.20-0.40... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090657 Fri, 09 Jan 2009 05:00:00 +0100 2090657 http://www.medworm.com/index.php?rid=2090656&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130243%26dopt%3DAbstract Authors: Woide D, Mayer V, Wachtmeister T, Hoehn N, Zink A, Koehler U, Thalhammer S Here we present a novel approach for horizontal transfer of single particles after laser microdissection. The developed technique is a single particle adsorbing system for highly selective and gentle horizontal transfer of microdissected fixed and living material. As mediated via low-pressure technology, the transfer process can be precisely controlled, thus facilitating horizontal particle transfer of any isolated material, e.g. tissue material, single cells or chromosomes, in addition to precise positioning for sample release. This collection method allows one to predefine target positions and enables material transfer without contamination to any planar microchip device. This contamination free trans... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090656 Fri, 09 Jan 2009 05:00:00 +0100 2090656 http://www.medworm.com/index.php?rid=2090655&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130244%26dopt%3DAbstract Authors: Yu ZT, Kamei KI, Takahashi H, Shu CJ, Wang X, He GW, Silverman R, Radu CG, Witte ON, Lee KB, Tseng HR The development of miniaturized cell culture platforms for performing parallel cultures and combinatorial assays is important in cell biology from the single-cell level to the system level. In this paper we developed an integrated microfluidic cell-culture platform, Cell-microChip (Cell-muChip), for parallel analyses of the effects of microenvironmental cues (i.e., culture scaffolds) on different mammalian cells and their cellular responses to external stimuli. As a model study, we demonstrated the ability of culturing and assaying several mammalian cells, such as NIH 3T3 fibroblast, B16 melanoma and HeLa cell lines, in a parallel way. For functional assays, first we tested dr... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2090655 Fri, 09 Jan 2009 05:00:00 +0100 2090655 http://www.medworm.com/index.php?rid=2062799&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19104940%26dopt%3DAbstract Authors: Yen HJ, Tseng CS, Hsu SH, Tsai CL Highly porous poly(D,L: -lactide-co-glycolide) (PLGA) scaffolds for cartilage tissue engineering were fabricated in this study using the fused deposition manufacturing (FDM) process and were further modified by type II collagen. The average molecular weight of PLGA decreased to about 60% of the original value after the melt-extrusion process. Type II collagen exhibited sponge-like structure and filled the macroporous FDM scaffolds. An increase of the fiber spacing resulted in an increase of the porosity. The storage modulus of FDM scaffolds with a large fiber spacing was comparable to that of the native porcine articular cartilage. Although the FDM hybrid scaffolds were swollen in various extents after 28 days of in vitro culture, the seeded c... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2062799 Tue, 23 Dec 2008 05:00:00 +0100 2062799 http://www.medworm.com/index.php?rid=2062798&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19104941%26dopt%3DAbstract Authors: Jen CP, Chen TW The manipulation of biological cells is essential to many biomedical applications. Insulator-based dielectrophoresis (iDEP) trapping consists of insulating structures which squeeze the electric field in a conductive solution to create a non-uniform electric field. The iDEP trapping microchip with the open-top microstructures was designed and fabricated in this work. For retaining the merit of microfabrication, the microelectrodes were deposited on the substrate to reduce the voltage required, due to the shortened spacing between them. The dielectrophoretic responses of both live and dead HeLa cells under different frequencies (100 Hz, 1 kHz and 1 MHz) have been investigated herein. The live cells exhibited negative dielectrophoresis at low frequencies of 100 Hz... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2062798 Tue, 23 Dec 2008 05:00:00 +0100 2062798 http://www.medworm.com/index.php?rid=2054348&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19096767%26dopt%3DAbstract Authors: Khang D, Carpenter J, Chun YW, Pareta R, Webster TJ Future biomaterials must simultaneously enhance tissue regeneration while minimizing immune responses and inhibiting infection. While the field of tissue engineering has promised to develop materials that can promote tissue regeneration for the entire body, such promises have not become reality. However, tissue engineering has experienced great progress due to the recent emergence of nanotechnology. Specifically, it has now been well established that increased tissue regeneration can be achieved on almost any surface by employing novel nano-textured surface features. Numerous studies have reported that nanotechnology accelerates various regenerative therapies, such as those for the bone, vascular, heart, cartilage, bladder an... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2054348 Fri, 19 Dec 2008 05:00:00 +0100 2054348 http://www.medworm.com/index.php?rid=2048573&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19089620%26dopt%3DAbstract Authors: Nikkhah M, Strobl JS, Peddi B, Agah M In this paper we studied differential adhesion of normal human fibroblast cells and human breast cancer cells to three dimensional (3-D) isotropic silicon microstructures and investigated whether cell cytoskeleton in healthy and diseased state results in differential adhesion. The 3-D silicon microstructures were formed by a single-mask single-isotropic-etch process. The interaction of these two cell lines with the presented microstructures was studied under static cell culture conditions. The results show that there is not a significant elongation of both cell types attached inside etched microstructures compared to flat surfaces. With respect to adhesion, the cancer cells adopt the curved shape of 3-D microenvironments while fibroblasts ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2048573 Wed, 17 Dec 2008 05:00:00 +0100 2048573 http://www.medworm.com/index.php?rid=2042086&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19085108%26dopt%3DAbstract Authors: Zhu S, Fu Y The hybrid Au-Ag triangular nanoparticles were proposed for the purpose of biosensing. To construct the nanoparticles, an Au thin film was deposited on top of the Ag nanoparticles supported with glass substrate. The hybrid nanoparticles can prevent oxidation of the pure Ag nanoparticles due to the Au protective layer caped on the Ag nanoparticles. The hybrid nanoparticles were designed using finite-difference and time-domain algorithm. Extinction spectra of the hybrid nanoparticles excited by visible light beam with plane wave were calculated, and the corresponding electric fields at peak position of the extinction spectra were expressed also. It is clear that the hybrid nanoparticles can excite the localized surface plasmon resonance wave which can be used to dete... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042086 Tue, 16 Dec 2008 05:00:00 +0100 2042086 http://www.medworm.com/index.php?rid=2042087&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19083100%26dopt%3DAbstract Authors: Eteshola E, Pandian RP, Lee SC, Kuppusamy P Crystalline lithium phthalocyanine (LiPc) can be used to sense oxygen. To enhance biocompatibility/stability of LiPc, we encapsulated LiPc in Teflon AF (TAF), cellulose acetate (CA), and polyvinyl acetate (PVAc) (TAF, previously used to encapsulate LiPc, was a comparator). We identified water-miscible solvents that don't dissolve LiPc crystals, but are solvents for the polymers, and encapsulated crystals by solvent evaporation. Oxygen sensitivity of films was characterized in vitro and in vivo. Encapsulation did not change LiPc oximetry properties in vitro at anoxic conditions or varying partial pressures of oxygen (pO(2)). EPR linewidth of encapsulated particles was linear with pO(2), responding to pO(2) changes quickly and reproduc... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042087 Sun, 14 Dec 2008 05:00:00 +0100 2042087 http://www.medworm.com/index.php?rid=2042089&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082898%26dopt%3DAbstract In this study, we have cultured HepG2 in a plate-type PDMS scaffold with a three-dimensional ordered microstructure optimally designed to allow cells to attach at a density of 10(8) cells/mL. After the first step of static open culture, the scaffold was sealed to simulate the in vivo oxygen supply, which is supplied only through the perfusion of medium. The oxygen consumption rate at various flow rates was measured. An average maximal cellular oxygen consumption rate of 3.4 x 10(-17) mol/s/cell was found, which is much lower than previously reported values for hepatocytes. Nevertheless, the oxygen concentration in the bulk stream was not the limiting factor. It has been further confirmed by the reported numerical model that the mass transport resistance on the surface of a cell that limits... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042089 Sat, 13 Dec 2008 05:00:00 +0100 2042089 http://www.medworm.com/index.php?rid=2042088&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19083099%26dopt%3DAbstract Authors: White WN, Raj A, Nguyen MD, Bertolone SJ, Sethu P Nucleated cell populations, including leukocytes and circulating endothelial cells, provide an ideal sample for studies seeking to understand the pathogenesis of diseases for development of drugs and treatments. Conventional leukocyte enrichment protocols have limitations with respect to selective cell loss and artifactual activation. An automated microfluidic device was developed for leukocyte enrichment from peripheral blood to ensure enumeration of high quality sample without cell loss or artifactual activation. Pre-clinical trials have shown the efficiency of the device to maximize cell yield and minimize artifactual activation in comparison to conventional techniques. Clinical validation and the ability of the microfluidic... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042088 Sat, 13 Dec 2008 05:00:00 +0100 2042088 http://www.medworm.com/index.php?rid=2042090&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082734%26dopt%3DAbstract Authors: Estes MD, Do J, Ahn CH This paper presents an on-chip magnetic cell sorting system for the sorting of cells based on a variety of surface markers. A polymer lab on a chip integrated with an electroplated array of Ni/Fe permalloy has been designed, fabricated, and characterized for the separation of cell substitutes at a variety of flow rates and incubation times. The system sequentially labels cell substitutes with magnetic beads and sorts them, repeating this process to sort for a variety of surface markers. Flow rates and incubation times were varied to characterize the system and produce the best combination of high specific capture and low nonspecific capture. The separation system developed on polymer is selective and efficient while being low cost, portable, and fabricat... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042090 Thu, 11 Dec 2008 05:00:00 +0100 2042090 http://www.medworm.com/index.php?rid=2042091&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082733%26dopt%3DAbstract In this study, microfluidics is used to probe the biorheological behaviour of breast cancer cells in an attempt to develop a method to distinguish between non-malignant and malignant cells. A microfabricated fluidic channel design consisting of a straight channel and two reservoirs was used to study the biorheological behaviour of benign breast epithelial cells (MCF-10A) and non-metastatic tumor breast cells (MCF-7). Quantitative parameters such as entry time (time taken for the cell to squeeze into the microchannel) and transit velocity (speed of the cell flowing through the microchannel) were defined and measured from these studies. Our results demonstrated that a simple microfluidic device can be used to distinguish the difference in stiffness between benign and cancerous breast cells. ... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2042091 Wed, 10 Dec 2008 05:00:00 +0100 2042091 http://www.medworm.com/index.php?rid=2029101&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19067174%26dopt%3DAbstract This report presents results from research towards a fully integrated, wireless neural interface consisting of a 100-channel microelectrode array, a custom-designed signal processing and telemetry IC, an inductive power receiving coil, and SMD capacitors. An integration concept for such a device was developed, and the materials and methods used to implement this concept were investigated. We developed a multi-level hybrid assembly process that used the Utah Electrode Array (UEA) as a circuit board. The signal processing IC was flip-chip bonded to the UEA using Au/Sn reflow soldering, and included amplifiers for up to 100 channels, signal processing units, an RF transmitter, and a power receiving and clock recovery module. An under bump metallization (UBM) using potentially biocompatible ma... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2029101 Wed, 10 Dec 2008 05:00:00 +0100 2029101 http://www.medworm.com/index.php?rid=2029102&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19067173%26dopt%3DAbstract Authors: Shein M, Greenbaum A, Gabay T, Sorkin R, David-Pur M, Ben-Jacob E, Hanein Y Standard micro-fabrication techniques which were originally developed to fabricate semi-conducting electronic devices were inadvertently found to be adequate for bio-chip fabrication suited for applications such as stimulation and recording from neurons in-vitro as well as in-vivo. However, cell adhesion to conventional micro-chips is poor and chemical treatments are needed to facilitate the interaction between the device surface and the cells. Here we present novel carbon nanotube-based electrode arrays composed of cell-alluring carbon nanotube (CNT) islands. These play a double role of anchoring neurons directly and only onto the electrode sites (with no need for chemical treatments) and facilitating... Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2029102 Mon, 08 Dec 2008 05:00:00 +0100 2029102 http://www.medworm.com/index.php?rid=2029100&cid=s_37610_169_f&fid=37610&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19067175%26dopt%3DAbstract This study shows statistically significant (P < 0.05) hypersensitivity of the UV20 CHO mutant to a DNA interstrand cross-linking agent (mitomycin C). Because the CFM is also capable of depositing proteins and other biomolecules to the individual microspots of the array we foresee capabilities of the 48 microspot CFM to multiplex 48 cell types with 48 chemical reagents all within the confines of a 60 mm(2) area. PMID: 19067175 [PubMed - as supplied by publisher] (Source: Biomedical Microdevices) Biomedical Microdevices journals http://www.medworm.com/rss/comments.php?id=2029100 Sun, 07 Dec 2008 05:00:00 +0100 2029100