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352 records returned

Polydiacetylene vesicles as a novel drug sustained-release system.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Aiming at the enhancement of the physicochemical stability as well as the sustained-release property of conventional liposomes, a novel polymerized vesicular carrier, 10,12-pentacosadiynoic acid (PCDA) vesicles, loaded with paclitaxel as a model hydrophobic drug has been successfully constituted by incorporation of a polymerizable diacetylene into the lipid bilayer vesicles. The polymerized vesicles have been characterized in terms of particle size distribution and zeta-potential. Altering their lipid composition causes the zeta-potential to change from -3+/-1mV to more than -25mV, with a concomitant change in particle...
Source: Colloids and Surfaces - November 5, 2009 Category: Biotechnology Authors: Guo C, Liu S, Dai Z, Jiang C, Li W Tags: Colloids Surf B Biointerfaces Source Type: journals

Study of a binary interpenetrated polymeric complex by correlation of rheological parameters with zeta potential and conductivity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The interpenetrated macromolecular chains complexation between poly(aspartic acid) and poly(vinyl alcohol) in aqueous solution it was investigated. The interpolymer complexation process was evaluated through dynamic rheology. The aspects concerning the stability of the tested homopolymers and the prepared interpolymeric complex there were achieved from the evaluation of the aqueous solutions'zeta potential and also by determining the pH influence upon the zeta potential and the conductivity. The data obtained through the rheological dynamic measurements were correlated with the composition of the polymeric mixture, the...
Source: Colloids and Surfaces - November 5, 2009 Category: Biotechnology Authors: Nita LE, Chiriac AP, Neamtu I, Bercea M Tags: Colloids Surf B Biointerfaces Source Type: journals

The effect of underlying octadecylamine monolayer on the DNA conformation on the graphite surface.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
DNA was immobilized on highly oriented pyrolytic graphite (HOPG) surfaces modified in octadecylamine (ODA) vapor. ODA molecules, deposited from the vapor phase onto HOPG form a nanostructured surface, which was utilized as a template for DNA adsorption. Peculiarities of double- and single-stranded DNA adsorption on these surfaces were investigated with atomic force microscopy (AFM) both in air, liquid and under different salt conditions. AFM images of DNA molecules immobilized on octadecylamine modified HOPG reveal a segmented shape of biopolymers: it constitutes straight segments with sharp turns at angles 120 degrees...
Source: Colloids and Surfaces - November 5, 2009 Category: Biotechnology Authors: Dubrovin EV, Gerritsen JW, Zivkovic J, Yaminsky IV, Speller S Tags: Colloids Surf B Biointerfaces Source Type: journals

Studies on interaction of colloidal Ag nanoparticles with Bovine Serum Albumin (BSA).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study established that tailoring the concentration of BSA and pH of the interaction it was possible to reduce aggregation of nanoparticles. Biofunctionalized Ag nanoparticles with reduced aggregation will be more amenable towards bio-sensing applications. PMID: 19896812 [PubMed - as supplied by publisher] (Source: Colloids and Surfaces)
Source: Colloids and Surfaces - November 5, 2009 Category: Biotechnology Authors: Ravindran A, Singh A, Raichur AM, Chandrasekaran N, Mukherjee A Tags: Colloids Surf B Biointerfaces Source Type: journals

Effect of edelfosine on tumor and normal cells model membranes-A comparative study.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This work is aimed at comparing the effect of edelfosine (Ed) on normal and tumor cell membrane imitated by the Langmuir monolayers prepared from cholesterol and phosphatidylcholines. To keep the differences in the fluidity of these membranes, model membrane of normal cell has been composed from saturated phospholipid (DPPC) and contained a higher proportion of cholesterol (cholesterol:DPPC=0.67) than tumor cell model membranes prepared from unsaturated phosphatidylcholine (cholesterol:POPC=0.25). The results proved that the incorporation of edelfosine modifies the organization and interactions between molecules in bot...
Source: Colloids and Surfaces - November 5, 2009 Category: Biotechnology Authors: Hąc-Wydro K, Dynarowicz-Łątka P Tags: Colloids Surf B Biointerfaces Source Type: journals

Influence of (bi)carbonate on bacterial interaction with quartz and metal oxide-coated surfaces.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study investigated the influence of (bi)carbonate on the adhesion of bacteria (Bacillus subtilis ATCC 6633) to quartz, aluminum oxide-coated, and iron oxide-coated surfaces. Column experiments were conducted at various NaHCO(3) concentrations. Bacterial breakthrough curves were obtained by monitoring effluent, and mass recoveries were quantified from these curves. With NaHCO(3) concentrations varying from 0 to 200mM, the corresponding effective ionic strength varied from 0 to 149.0mM and solution pH from 6.2 to 8.7. Results show that at low and intermediate NaHCO(3) concentrations (1 and 10mM), bacterial adhesion to n...
Source: Colloids and Surfaces - November 4, 2009 Category: Biotechnology Authors: Park SJ, Kim SB Tags: Colloids Surf B Biointerfaces Source Type: journals

A quantitative study of the enzymatic activity of horseradish peroxidase at a planar poly(acrylic acid) brush.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, HRP was used to catalyze the oxidation of Amplex Red to resorufin by hydrogen peroxide. The fluorescence of resorufin was recorded using a microplate reader. As compared to a bare silica surface, the enzymatic activity of HRP is higher by more than one order of magnitude at a PAA brush. This increase results from a higher degree of adsorption and a reasonable preservation of the HRP activity. Upon adsorption at a PAA brush from a 20mU/mL (0.1mug/mL) solution, the molecular enzymatic activity of HRP is reduced to about 11%. However, when a HRP molecule is desorbed from a PAA brush by increasing the ionic stre...
Source: Colloids and Surfaces - November 4, 2009 Category: Biotechnology Authors: Reichhart C, Czeslik C Tags: Colloids Surf B Biointerfaces Source Type: journals

Surface modification with BSA blocking based on in situ synthesized gold nanoparticles in poly(dimethylsiloxane) microchip.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A stable BSA blocking poly(dimethylsiloxane) (PDMS) microchannel was prepared based on in situ synthesized PDMS-gold nanoparticles composite films. The modified microchip could successfully suppress protein adsorption. The assembly was followed by contact angle, charge-coupled device (CCD) imaging, electroosmotic flow (EOF) measurements and electrophoretic separation methods. Contact angle measurements revealed the coated surface was hydrophilic, water contact angle for coated chips was 45.2 degrees compared to a water contact angle for native PDMS chips of 88.5 degrees . The coated microchips exhibited reproducible an...
Source: Colloids and Surfaces - November 4, 2009 Category: Biotechnology Authors: Fan DH, Yuan SW, Shen YM Tags: Colloids Surf B Biointerfaces Source Type: journals

Effects of disordered hemispherical micropatterns on Staphylococcus epidermidis biofilm formation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Surfaces which have physical patterns in the scale of bacteria cells have been shown to influence the microorganism's adhesion and biofilm formation characteristics. Layer-by-layer self-assembly was utilized to create disordered hemispherical patterns on poly(dimethylsiloxane) with a feature size of 0.5mum, 1.0mum and 2.0mum. The effects of pattern size on the retention and biofilm formation of Staphylococcus epidermidis were examined as a function of culture time. The 1.0mum pattern significantly reduced biofilm surface coverage by approximately 30% after 5h of culture in comparison to that on an unpatterned surface w...
Source: Colloids and Surfaces - November 3, 2009 Category: Biotechnology Authors: Ihnen AC, Lee JH, Lee WY Tags: Colloids Surf B Biointerfaces Source Type: journals

Self-microemulsifying and microemulsion systems for transdermal delivery of indomethacin: Effect of phase transition.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study investigated the transdermal delivery of indomethacin (model drug) from self-microemulsifying system, microemulsions and their phase transition systems. The study selected five formulations with fixed surfactant-oil ratio and increasing water content. These included a water free self-microemulsifying drug delivery system (SMEDDS), microemulsions containing water at 5% (w/w) (ME 5%) or at 10% (w/w) (ME 10%), a liquid crystalline formulation containing water at 30% (w/w) (LC) and coarse emulsion containing water at 80% (w/w) (EM). To clarify the results the study evaluated a microemulsion containing 10% (w/w) of r...
Source: Colloids and Surfaces - October 13, 2009 Category: Biotechnology Authors: El Maghraby GM Tags: Colloids Surf B Biointerfaces Source Type: journals

Amphiphilic drug persuaded collapse of polyvinylpyrrolidone and poly(ethylene glycol) chains: A dynamic light scattering study.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Light scattering has proved to be useful in characterizing colloidal systems. We have studied the interaction between an amphiphilic drug, amitriptyline hydrochloride (AMT), and neutral polymers, polyvinylpyrrolidone (PVP) and poly(ethylene glycol) (PEG), using the dynamic light scattering (DLS) technique. AMT was found to interact with PVP more strongly than PEG. A large decrease of the size of aggregates upon increase of AMT concentration indicates a successive collapse of the polymer conformation. The partial negatively charged oxygen atoms, present in the amide group of PVP, were believed to be responsible for the...
Source: Colloids and Surfaces - October 12, 2009 Category: Biotechnology Authors: Ali MS, Ghosh G, Kabir-Ud-Din Tags: Colloids Surf B Biointerfaces Source Type: journals

Formulating fluticasone propionate in novel PEG-containing nanostructured lipid carriers (PEG-NLC).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study was to develop nanostructured lipid carriers (NLC) for topical delivery of fluticasone propionate (FP) with the aim to further improve the safety profile and decrease the adverse-side effects commonly reported in topical corticotherapy. NLC are colloidal drug-carriers consisting of a blend of a solid lipid and a small amount of liquid lipid since these carriers have proved to be effective in epidermal targeting in particular of glucocorticoids. NLC consisting of glyceryl palmito-stearate, and PEG-containing medium chain triglycerides mixture, stabilised by polysorbate 80 and soybean phosphatidylch...
Source: Colloids and Surfaces - October 8, 2009 Category: Biotechnology Authors: Doktorovová S, Araújo J, Garcia ML, Rakovský E, Souto EB Tags: Colloids Surf B Biointerfaces Source Type: journals

Adhesion, friction and wear characterization of skin and skin cream using atomic force microscope.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, a systematic characterization of the friction and adhesion properties of skin and skin cream was carried out, which is essential to develop better skin care products and advance biological, dermatology, and cosmetic science. Since cream rheology is expected to be a function of its thickness as well as the velocity and normal load during its application, friction and adhesion experiments were performed at a range of cream film thickness, velocity, and normal load in order to study their effect on virgin skin and cream treated skin. Since environmental dependence of skin and skin cream is of importance, the ef...
Source: Colloids and Surfaces - October 6, 2009 Category: Biotechnology Authors: Tang W, Bhushan B Tags: Colloids Surf B Biointerfaces Source Type: journals

Pear fruit extract-assisted room-temperature biosynthesis of gold nanoplates.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this paper, a single-step room-temperature biosynthetic route for producing gold nanostructures using pear fruit is reported. The alkaline conditions of the pear fruit extract induced gold nanoparticles with plate-like morphologies. Successfully biosynthesized triangular and hexagonal nanoplates were observed, elegantly assembled with hexagonal gold nanoparticles. Nanostructure size, crystal nature, purity and morphologies were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS) and energy dispersive X-ray analysis (E...
Source: Colloids and Surfaces - October 6, 2009 Category: Biotechnology Authors: Ghodake GS, Deshpande NG, Lee YP, Jin ES Tags: Colloids Surf B Biointerfaces Source Type: journals

S-layer templated bioinspired synthesis of silica.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The current understanding of the molecular mechanisms involved in the bioinspired formation of silica structures laid foundation for investigating the potential of the S-layer protein SbpA from Lysinibacillus sphaericus CCM 2177 as catalyst, template and scaffold for the generation of novel silica architectures. SbpA reassembles into monomolecular lattices with square (p4) lattice symmetry and a lattice constant of 13.1nm. Silica layers on the S-layer lattice were formed using tetramethoxysilane (TMOS) and visualized by transmission electron microscopy. In situ quartz crystal microbalance with dissipation monitoring (Q...
Source: Colloids and Surfaces - October 2, 2009 Category: Biotechnology Authors: Göbel C, Schuster B, Baurecht D, Sleytr UB, Pum D Tags: Colloids Surf B Biointerfaces Source Type: journals

Formation and cross-linking of fibrinogen layers monitored with in situ spectroscopic ellipsometry.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Thick matrices of fibrinogen with incorporation of a matrix metalloproteinase inhibitor were covalently bonded on functionalized silicon surfaces using an ethyl-3-dimethyl-aminopropyl-carbodiimide and N-hydroxy-succinimide affinity ligand coupling chemistry. The growth of the structure was followed in situ using dynamic ellipsometry and characterized at steady-state with spectroscopic ellipsometry. The growth was compared with earlier work on ex situ growth of fibrinogen layers studied by single wavelength ellipsometry. It is found that in situ growth and ex situ growth yield different structural properties of the form...
Source: Colloids and Surfaces - October 2, 2009 Category: Biotechnology Authors: Berlind T, Poksinski M, Tengvall P, Arwin H Tags: Colloids Surf B Biointerfaces Source Type: journals

Tat peptide mediated cellular uptake of SiO(2) submicron particles.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Internalization of nano- and microparticles into live cells correlates closely with their potential applications, functions, cytotoxicity and intracellular drug delivery. Particularly, delivery of a large variety of cargoes such as proteins, peptides, nucleic acids and small particles into cells could be enhanced by some ligands such as Tat peptide. In this work, the ability of Tat mediated cellular uptake was assessed. The Tat peptide was covalently immobilized to fluorescein tagged SiO(2) particles (FITC-SiO(2)-NH(2) particles) with a diameter of 200nm. BCA protein assay determined that the grafting amount of the Tat...
Source: Colloids and Surfaces - October 1, 2009 Category: Biotechnology Authors: Mao Z, Wan L, Hu L, Ma L, Gao C Tags: Colloids Surf B Biointerfaces Source Type: journals

Fabrication of nanomicelle with enhanced solubility and stability of camptothecin based on alpha,beta-poly[(N-carboxybutyl)-l-aspartamide]-camptothecin conjugate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This research is aimed to develop a nanomicelle delivery system in order to enhance the solubility and stability of camptothecin (CPT) in aqueous media. In this case, alpha,beta-poly[(N-carboxybutyl)-l-aspartamide] (PBAsp)-CPT was conjugated by the esterification between PBAsp and 20-OH of CPT, and hence used to fabricate nanomicelles with a particle size between the pore size of blood capillary in normal tissue and that in tumor tissue. It was worthy of note that the drug-loaded system of PBAsp-CPT nanomicelle improved the solubility and stability of CPT in aqueous media. However, with an increase of the CPT loading i...
Source: Colloids and Surfaces - September 25, 2009 Category: Biotechnology Authors: Fan N, Duan K, Wang C, Liu S, Luo S, Yu J, Huang J, Li Y, Wang D Tags: Colloids Surf B Biointerfaces Source Type: journals

Candida rugosa lipase Lip1-polyethyleneglycol interaction and the relation with its partition in aqueous two-phase systems.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The interaction between a lipase from Candida rugosa (Lip1) and polyethyleneglycols of different molecular masses was studied using fluorescence and circular dichroism approaches in order to be applied to the analysis of the enzyme partition mechanism in aqueous two-phase systems of polyethyleneglycol-potassium phosphate. The decrease of the partition coefficients with the polyethyleneglycol molecular mass showed that the enzyme partition is driven by the excluded volume effect and not by the enzyme-polymer interaction. The polymer did not affect the secondary and tertiary structure of the enzyme nor its biological act...
Source: Colloids and Surfaces - September 25, 2009 Category: Biotechnology Authors: Bassani G, Fuciños P, Picó G, Farruggia B Tags: Colloids Surf B Biointerfaces Source Type: journals

Surface plasmon resonance biosensor based on Au nanoparticle in titania sol-gel membrane.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel surface plasmon resonance (SPR) biosensor for the determination of human IgG was introduced. The biosensor was prepared with three layers of titania sol-gel membrane by vapor deposition. The colloid Au nanoparticle (AuNP) was immobilized in the second layer of titania membrane and the AuNP coupled with rabbit anti-human IgG was encapsulated in the third layer. The AuNP in the second layer of titania membrane was proved to be effective in the sensitivity enhancement of SPR biosensor. The lowest concentration that could be detected obtained by the biosensor with AuNP is about eight times lower than that obtained ...
Source: Colloids and Surfaces - September 25, 2009 Category: Biotechnology Authors: Wang J, Wang L, Sun Y, Zhu X, Cao Y, Wang X, Zhang H, Song D Tags: Colloids Surf B Biointerfaces Source Type: journals

Use of hydrophobins in formulation of water insoluble drugs for oral administration.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The poor water solubility of many drugs requires a specific formulation to achieve a sufficient bioavailability after oral administration. Suspensions of small drug particles can be used to improve the bioavailability. We here show that the fungal hydrophobin SC3 can be used to make suspensions of water insoluble drugs. Bioavailability of two of these drugs, nifedipine and cyclosporine A (CyA), was tested when administered as a SC3-based suspension. SC3 (in a 1:2 (w/w) drug:SC3 ratio) or 100% PEG400 increased the bioavailability of nifedipine to a similar degree (6+/-2- and 4+/-3-fold, respectively) compared to nifedip...
Source: Colloids and Surfaces - September 25, 2009 Category: Biotechnology Authors: Haas Jimoh Akanbi M, Post E, Meter-Arkema A, Rink R, Robillard GT, Wang X, Wösten HA, Scholtmeijer K Tags: Colloids Surf B Biointerfaces Source Type: journals

Evaluation of boronate-containing polymer brushes and gels as substrates for carbohydrate-mediated adhesion and cultivation of animal cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Boronate-containing thin polyacrylamide gels (B-Gel), polymer brushes (B-Brush) and chemisorbed organosilane layers (B-COSL) were prepared on the surface of glass slides and studied as substrates for carbohydrate-mediated cell adhesion. B-COSL- and B-Brush-modified glass samples exhibited multiple submicron structures densely and irregularly distributed on the glass surface, as found by scanning electron microscopy and atomic force microscopy. B-Gel was ca. 0.1mm thick and contained pores with effective size of 1-2mum in the middle and of 5-20mum on the edges of the gel sample as found by confocal laser scanning micros...
Source: Colloids and Surfaces - September 25, 2009 Category: Biotechnology Authors: Ivanov AE, Kumar A, Nilsang S, Aguilar MR, Mikhalovska LI, Savina IN, Nilsson L, Scheblykin IG, Kuzimenkova MV, Galaev IY Tags: Colloids Surf B Biointerfaces Source Type: journals

Dextrin nanoparticles: Studies on the interaction with murine macrophages and blood clearance.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The uptake of nanoparticles by cells of the mononuclear phagocytic system limits its use as colloidal drug carriers, reducing the blood circulation time and the ability to reach biological targets. In this work, the interaction between dextrin nanoparticles - recently developed in our laboratory - and murine bone marrow-derived macrophages was evaluated. Cytotoxicity and nitric oxide production were studied, using the MTT assay and the Griess method, respectively. FITC labelled nanoparticles were used to assess the phagocytic uptake and blood clearance after intravenous injection. The phagocytic uptake was analysed in ...
Source: Colloids and Surfaces - September 24, 2009 Category: Biotechnology Authors: Gonçalves C, Torrado E, Martins T, Pereira P, Pedrosa J, Gama M Tags: Colloids Surf B Biointerfaces Source Type: journals

Competitive adsorption of toxic heavy metal contaminants by gum kondagogu (Cochlospermum gossypium): A natural hydrocolloid.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Gum kondagogu (Cochlospermum gossypium), a naturally occurring tree biopolymer, is exploited as a biosorbent to remove metal ions from aqueous solutions. The removal efficiency of toxic metals by gum kondagogu was determined quantitatively in the order Cd(2+)>Cu(2+)>Fe(2+)>Se(2+)>Pb(2+)>total Cr>Ni(2+)>Zn(2+)>Co(2+)>As(2+) at pH 5.0+/-0.1 and temperature 25+/-2 degrees C by inductively coupled plasma-mass spectrometry (ICP-MS). The biosorption (%) of various metal ions tested was found to be in the range of 97.3-16.7%, at pH 5.0. The morphological and mechanisms of interaction of toxic metal ...
Source: Colloids and Surfaces - September 24, 2009 Category: Biotechnology Authors: Vinod VT, Sashidhar RB, Sukumar AA Tags: Colloids Surf B Biointerfaces Source Type: journals

l-Cysteine-induced photoluminescence enhancement of CdSe/ZnSe quantum dots in aqueous solution.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
l-Cysteine molecules dramatically enhance the photoluminescence of colloidal CdSe/ZnSe quantum dots (i.e., (CTAB/TOPO)QD). Based on our spectroscopic studies of temporal variations in QD quantum yields as well as the in situ infrared spectral features of QDs, we propose that adsorption and rearrangement of l-cysteine molecules at the QD-water interface induces the observed unusual enhancement of the photoluminescence quantum yield. Upon addition of l-cysteine to the (CTAB/TOPO)QD solution, the adsorption of l-cysteine to the (CTAB/TOPO)QD colloidal particles is driven by the formation of a kinetically favorable interme...
Source: Colloids and Surfaces - September 22, 2009 Category: Biotechnology Authors: Park C, Yoon TH Tags: Colloids Surf B Biointerfaces Source Type: journals

Preparation of chitosan microspheres by ionotropic gelation under a high voltage electrostatic field for protein delivery.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Biodegradable microspheres have been widely used in drug/protein delivery system. In this paper, a modified ionotropic gelation method combined with a high voltage electrostatic field was developed to prepare protein-loaded chitosan microspheres. Bovine serum albumin (BSA) was chosen as a model protein. The preparation process and major parameters were discussed and optimized. The morphology, particle size, encapsulation efficiency and in vitro release behavior of the prepared microspheres were investigated. The results revealed that the microspheres exhibited good sphericity and dispersity when the mixture of sodium t...
Source: Colloids and Surfaces - September 22, 2009 Category: Biotechnology Authors: Ma L, Liu C Tags: Colloids Surf B Biointerfaces Source Type: journals

Simulations of lipid transfer between a supported lipid bilayer and adsorbing vesicles.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recent experiments demonstrate transfer of lipid molecules between a charged, supported lipid membrane (SLB) and vesicles of opposite charge when the latter adsorb on the SLB. A simple phenomenological bead model has been developed to simulate this process. Beads were defined to be of three types, 'n', 'p', and '0', representing POPS (negatively charged), POEPC (positively charged), and POPC (neutral but zwitterionic) lipids, respectively. Phenomenological bead-bead interaction potentials and lipid transfer rate constants were used to account for the overall interaction and transfer kinetics. Using different bead mixtu...
Source: Colloids and Surfaces - September 22, 2009 Category: Biotechnology Authors: Dimitrievski K, Kasemo B Tags: Colloids Surf B Biointerfaces Source Type: journals

How surface composition of high milk proteins powders is influenced by spray-drying temperature.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
High milk proteins powders are common ingredients in many food products. The surface composition of these powders is expected to play an essential role during their storage, handling and/or final application. Therefore, an eventual control of the surface composition by modifying the spray-drying temperature could be very useful in the improvement of powder quality and the development of new applications. For this purpose, the influence of five spray-drying temperatures upon the surface composition of the powders was investigated by X-ray photoelectron spectroscopy. The major milk proteins were studied: native micellar ...
Source: Colloids and Surfaces - September 19, 2009 Category: Biotechnology Authors: Gaiani C, Morand M, Sanchez C, Therany EA, Jacquot M, Schuck P, Jeantet R, Scher J Tags: Colloids Surf B Biointerfaces Source Type: journals

Effect of biomedical organic compounds on the setting reaction of calcium phosphates.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In the present study, the effect of biomedical organic compounds (starch, sodium alginate, chitosan and gelatin) on the hydration of calcium phosphates was studied using X-ray diffraction, infrared spectroscopy, scanning electron microscopy and XPS analysis. Amorphous calcium phosphate (ACP) was prepared by a mechanochemical route and mixed with biomedical organic compounds. A solidification reaction occurred between ACP and dicalcium phosphate dihydrate (DCPD); the hydration product was poorly crystallized hydroxyapatite (HA). During the setting reaction of ACP and DCPD, the presence of biomedical organic compounds ha...
Source: Colloids and Surfaces - September 18, 2009 Category: Biotechnology Authors: Yu T, Ye J, Gao C, Yu L, Wang Y Tags: Colloids Surf B Biointerfaces Source Type: journals

Blood compatibility evaluation of poly(d,l-lactide-co-beta-malic acid) modified with the GRGDS sequence.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Endothelialization is an ideal approach to improve the blood compatibility of synthetic polymers. However, cell detachment is inevitable under shear flow conditions. Therefore, the issue of blood compatibility needs to be addressed for both the bare and the endothelialized polymer. RGD-containing polymer P-GS5 was synthesized by modification of poly(d,l-lactide-co-beta-malic acid) (PLMA) with the peptide GRGDS. The compositions, molecular weights and hydrophilicities of poly(d,l-lactide) (PDLLA), PLMA, and P-GS5 were characterized by nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), gel-permeati...
Source: Colloids and Surfaces - September 18, 2009 Category: Biotechnology Authors: Liu Y, Wang W, Wang J, Wang Y, Yuan Z, Tang S, Liu M, Tang H Tags: Colloids Surf B Biointerfaces Source Type: journals

Phytochemical mediated gold nanoparticles and their PTP 1B inhibitory activity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Current discovery demonstrates the rapid formation of gold nanoparticles with guavanoic acid a phytochemical of Psidium guajava (Pg). The pharmacological capabilities of the phytochemicals present in the leaves of Pg and their ability to generate gold nanoparticles is presented herein. The new genre of green nanoparticles exhibit remarkable Protein Tyrosine Phosphatase 1B (PTP 1B) inhibitory activity and in vitro stability in various physiological medium including saline, histidine, cysteine, bovine serum albumin (BSA), human serum albumin (HSA) and buffers (pH 5, 7 and 9). It is predicted that this new technology will...
Source: Colloids and Surfaces - September 15, 2009 Category: Biotechnology Authors: Khaleel Basha S, Govindaraju K, Manikandan R, Ahn JS, Bae EY, Singaravelu G Tags: Colloids Surf B Biointerfaces Source Type: journals

Surface transformation of silicon-doped hydroxyapatite immersed in culture medium under dynamic and static conditions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A comparative study of in vitro bioactivity of hydroxyapatite (HA) and silicon-doped hydroxyapatite (SiHA) has been carried out by immersion in a cell culture medium with or without fetal bovine serum during 14 days in static and dynamic conditions. A specific bioreactor was developed for the experiments in dynamic conditions. Ceramic surface transformations were characterized by electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy before and after immersion. The monitoring of calcium, phosphate and proteins in immersion medium was also done during the experiment. The two hydroxyapatite sur...
Source: Colloids and Surfaces - September 14, 2009 Category: Biotechnology Authors: Silva HM, Mateescu M, Ponche A, Damia C, Champion E, Soares G, Anselme K Tags: Colloids Surf B Biointerfaces Source Type: journals

Ferroelectric BaTiO(3) nanoparticles: Biosynthesis and characterization.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A new low-cost, green and reproducible Lactobacillus sp. assisted biosynthesis of BaTiO(3) nanoparticles is reported. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of BaTiO(3) nanoparticles. The apparent crystallite size and lattice strain are estimated from Williamson-Hall approach. XRD analysis of the compound indicated the formation of a single-phase tetragonal structure. Individual nanoparticles as well as a few aggregate having the size of 20-80nm are found. A possible involved mechanism for the biosynthesis of nano-BaTiO(3) has also been proposed in which ROS as well...
Source: Colloids and Surfaces - September 14, 2009 Category: Biotechnology Authors: Jha AK, Prasad K Tags: Colloids Surf B Biointerfaces Source Type: journals

Using thiophilic magnetic beads in purification of antibodies from human serum.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we presented a novel method to isolate immunoglobulin G from human serum based on the utilization of thiophilic magnetic polymer beads. Micron-sized magnetic beads with paramagnetic properties were synthesized by microsuspension polymerization in the presence of modified magnetite. After the thiophilic ligand of 2-mercaptonicotinic acid was modified on the surface, these magnetic beads exhibited a strong specificity towards immunoglobulin G in a salt-independent manner. Then, antibodies could be directly isolated from human serum in batch-wise mode with the assistance of magnetic decantation. The purity of t...
Source: Colloids and Surfaces - September 14, 2009 Category: Biotechnology Authors: Qian H, Li C, Lin Z, Zhang Y Tags: Colloids Surf B Biointerfaces Source Type: journals

Transdermal delivery of anticancer drug caffeine from water-in-oil nanoemulsions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recently caffeine has been investigated for the treatment of various types of cancers upon oral administration. There is also some evidence that dermally applied caffeine can protect the skin from skin cancer caused by sun exposure. Therefore nanoemulsion formulation of caffeine for transdermal drug delivery was developed and evaluated in the present investigation. Different w/o nanoemulsion formulations of caffeine were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized for morphology, droplet size, viscosity and refractive index. The invitro skin permeation studies were ...
Source: Colloids and Surfaces - September 12, 2009 Category: Biotechnology Authors: Shakeel F, Ramadan W Tags: Colloids Surf B Biointerfaces Source Type: journals

Adsorption behavior of ferritin and buffer components, buffer agents and salts, onto silane-coupled silicon substrate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Fixation of ferritin using amino-silane modified substrates is effective, but salt and alkali ions of the buffer can contaminate substrates, inhibiting the sensing and fabrication of nano-electronic devices. To avoid adsorption of salts and alkali ions, buffer solutions have been replaced by pure water or alkali-metal-ion-free buffer. However, proteins in such solutions are sometimes denatured. Therefore, we developed a substrate which adsorbs ferritin but does not adsorb contaminants such as salts and alkali metal-ions contained in the buffer. Adsorption of ferritin was achieved by using a buffer with a high ion stren...
Source: Colloids and Surfaces - September 10, 2009 Category: Biotechnology Authors: Fukuta M, Yamashita I Tags: Colloids Surf B Biointerfaces Source Type: journals

Biodegradable polymeric nanoparticles based drug delivery systems.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Biodegradable nanoparticles have been used frequently as drug delivery vehicles due to its grand bioavailability, better encapsulation, control release and less toxic properties. Various nanoparticulate systems, general synthesis and encapsulation process, control release and improvement of therapeutic value of nanoencapsulated drugs are covered in this review. We have highlighted the impact of nanoencapsulation of various disease related drugs on biodegradable nanoparticles such as PLGA, PLA, chitosan, gelatin, polycaprolactone and poly-alkyl-cyanoacrylates. PMID: 19782542 [PubMed - as supplied by publisher] (Sour...
Source: Colloids and Surfaces - September 7, 2009 Category: Biotechnology Authors: Kumari A, Yadav SK, Yadav SC Tags: Colloids Surf B Biointerfaces Source Type: journals

New sucrose cocoate based vesicles: Preparation characterization and skin permeation studies.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A commercial sucrose cocoate surfactant was used to obtain a new vesicular system for transdermal drug delivery. The preparation, the dimensional and morphological characterizations and the skin permeation profile of these new niosomes were evaluated. Moreover we studied the possible employment of mixture of sucrose cocoate and cholesterol at different weigh ratios for the vesicles preparation and we analyzed the influence of cholesterol on niosomes properties. Diclofenac and Sulfadiazine were used as model drugs. Results suggest that sucrose cocoate was able to form vesicles in the presence or not of cholesterol and t...
Source: Colloids and Surfaces - September 7, 2009 Category: Biotechnology Authors: Tavano L, Muzzalupo R, Cassano R, Trombino S, Ferrarelli T, Picci N Tags: Colloids Surf B Biointerfaces Source Type: journals

Characterisation of the de-agglomeration effects of bovine serum albumin on nanoparticles in aqueous suspension.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper describes the use of nanoparticle characterisation tools to evaluate the interaction between bovine serum albumin (BSA) and dispersed nanoparticles in aqueous media. Dynamic light scattering, zeta-potential measurements and scanning electron microscopy were used to probe the state of zinc oxide (ZnO) and titanium dioxide (TiO(2)) nanoparticles in the presence of various concentrations of BSA, throughout a three-day period. BSA was shown to adhere to ZnO but not to TiO(2). The adsorption of BSA led to subsequent de-agglomeration of the sub-micron ZnO clusters into smaller fragments, even breaking them up into...
Source: Colloids and Surfaces - September 5, 2009 Category: Biotechnology Authors: Tantra R, Tompkins J, Quincey P Tags: Colloids Surf B Biointerfaces Source Type: journals

Interaction between phospholipids bilayer and chitosan in liposomes investigated by (31)P NMR spectroscopy.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The interaction between chitosan and the polar head of phosphatidylcholine (PC) is discussed for a composite nanovesicle obtained by incorporating chitosan in the organic phase before PC self-assembling. Nanovesicles free of chitosan are studied in parallel to allow the comparison concerning modifications produced on the composite system. Zeta Potential increases in the presence of chitosan and with the increase in its concentration proving the localization of the polymer over the external surface of the vesicle as one interaction site. A (31)P resonance around 0ppm, characteristic of the system, is reduced with additi...
Source: Colloids and Surfaces - September 3, 2009 Category: Biotechnology Authors: Mertins O, Schneider PH, Pohlmann AR, da Silveira NP Tags: Colloids Surf B Biointerfaces Source Type: journals

Preparation and characterization of a polymeric (PLGA) nanoparticulate drug delivery system with simultaneous incorporation of chemotherapeutic and thermo-optical agents.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of this study was to develop biodegradable poly(dl-lactide-co-glycolic acid) (PLGA) nanoparticles simultaneously loaded with indocyanine green (ICG) and doxorubicin (DOX). The modified oil in water single emulsion solvent evaporation method was used. To enhance the incorporation of both agents and control particle size, four independent processing parameters including amount of polymer, initial ICG content, initial DOX content, and concentration of poly-vinyl alcohol (PVA) were investigated. The ICG and DOX entrapment in nanoparticles as well as the nanoparticle size were determined. The nanoparticles produce...
Source: Colloids and Surfaces - September 3, 2009 Category: Biotechnology Authors: Manchanda R, Fernandez-Fernandez A, Nagesetti A, McGoron AJ Tags: Colloids Surf B Biointerfaces Source Type: journals

Probe chemistry effect on surface properties of asymmetric-phase lipid bilayers.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Phospholipid bilayers were formed on mica using Langmuir-Blodgett technique and liposome fusion, as a model system for biomembranes. Nanometer-scale surface physical properties were quantitatively characterized upon the different phases of the monolayers with the different surface chemistry. The less hydration/steric forces were observed at the liquid-phase of the lipid layer than at the solid-phase for the OH-modified probe, while the forces with the CH(3)-modified probe were independent of the mechanical stability of the layer. The forces appear to be related to the surface chemistry of the probe to the layer as well...
Source: Colloids and Surfaces - September 3, 2009 Category: Biotechnology Authors: Park JW Tags: Colloids Surf B Biointerfaces Source Type: journals

In honour of Professor Hans Kuhn.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19758791 [PubMed - as supplied by publisher] (Source: Colloids and Surfaces)
Source: Colloids and Surfaces - August 30, 2009 Category: Biotechnology Authors: Vollhardt D Tags: Colloids Surf B Biointerfaces Source Type: journals

Surface free energy and topography of mixed lipid layers on mica.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Langmuir-Blodgett/Schaefer (LB/LS) method, AFM technique and contact angle measurements were used to investigate the formation, structure and energetic properties of lipid films, which were constituted of single-component or binary systems formed by phospholipids: saturated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), unsaturated 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and triglyceride: glyceryl trioleate (GTO) or their mixture DPPC/DOPC and DPPC/GTO with a different DOPC or GTO molar ratio. The surface free energy and its components (apolar and polar interaction) for single and binary lipid mono- an...
Source: Colloids and Surfaces - August 27, 2009 Category: Biotechnology Authors: Jurak M, Chibowski E Tags: Colloids Surf B Biointerfaces Source Type: journals

Formulation and physicochemical characterization of poly(varepsilon-caprolactone) nanoparticles loaded with ftorafur and diclofenac sodium.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Even though conventional pharmacotherapy has been demonstrated to display very efficient activity against a wide variety of diseases, several active agents (e.g., anti-tumor drugs and non-steroidal anti-inflammatory drugs) are generally needed to be administered at high doses to elicit the required therapeutic action, simultaneously leading to severe side effects. This fact is usually due to unfavourable pharmacokinetic profiles (poor biological half-life) and to the possibility of induction of resistance. In order to increase the therapeutic activity of ftorafur and diclofenac sodium along with an overcome of their im...
Source: Colloids and Surfaces - August 25, 2009 Category: Biotechnology Authors: Arias JL, López-Viota M, Sáez-Fernández E, Ruiz MA Tags: Colloids Surf B Biointerfaces Source Type: journals

Fabrication of protein-anchoring surface by modification of Sio(2) with liposomal bilayer.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
SiO(2) surface was successfully modified with phospholipid bilayer for biocompatibility by covering the planar surface with vesicular liposomes. By applying heat to rupture the vesicle, they were converted into a planar form. To effectively decorate the bilayer with biological molecules such as a protein, BAM (biological anchor for membrane) was used as a linker. It is a linear assembly consisting of oleyl chain, polyethylene glycol, and NHS (N-hydroxysuccinimide). After a target protein (BSA) was conjugated with BAM by NHS replacement, the conjugate was effectively inserted to the phospholipid bilayer through the lipo...
Source: Colloids and Surfaces - August 25, 2009 Category: Biotechnology Authors: Cho HM, Cho DY, Jeon JY, Hwang SY, Ahn IS, Choo J, Lee EK Tags: Colloids Surf B Biointerfaces Source Type: journals

A sensitive DNA biosensor fabricated with gold nanoparticles/ploy (p-aminobenzoic acid)/carbon nanotubes modified electrode.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this work, we fabricated a sensitive electrochemical DNA biosensor for the detection of target DNA. Aminobenzoic acid (ABA) was firstly electropolymerized on the surface of the glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes with carboxyl groups (MWCNTs) by cyclic voltammetry (CV). Gold nanoparticles (AuNPs) were subsequently introduced to the surface of PABA-MWNTs composite film by electrochemical deposition mode. Probe DNA was immobilized on the surface of AuNPs through Au-S bond. Scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) were ...
Source: Colloids and Surfaces - August 24, 2009 Category: Biotechnology Authors: Zhang Y, Wang J, Xu M Tags: Colloids Surf B Biointerfaces Source Type: journals

Binding, inactivation, and adhesion forces between antimicrobial peptide cecropin P1 and pathogenic E. coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The antimicrobial peptide cecropin P1 (CP1) exhibits broad spectrum activity against planktonic bacteria, including Escherichia coli (E. coli). However, its activity when attached to a substrate has not been thoroughly studied. We immobilized CP1 to gold or silicon nitride, and studied how the method of attachment of peptide to the surface affected peptide interaction with and killing of the bacteria. Using the quartz crystal microbalance with dissipation monitoring (QCM-D), we characterized non-specific binding between CP1 to silicon nitride and gold, and covalent binding of cysteine-terminated CP1 (CP1-cys) to gold. ...
Source: Colloids and Surfaces - August 20, 2009 Category: Biotechnology Authors: Strauss J, Kadilak A, Cronin C, Mello CM, Camesano TA Tags: Colloids Surf B Biointerfaces Source Type: journals

An economically viable method for the removal of selected divalent metal ions from aqueous solutions using activated rice husk.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Biosorption of divalent metal ions, i.e. Pb(II), Cd(II), Zn(II) and Cu(II) onto rice husk activated (RHA) is investigated over pH range (1-10) via batch adsorption technique. The chemical and thermal activation of rice husk with 0.1M HNO(3) and 1M K(2)CO(3) at 473K enhanced the removal efficiency of RHA (35+/-2.1-99+/-0.5%, 33+/-1.2-97+/-0.6%, 32+/-1.3-96+/-0.8% and 28+/-1.8-95+/-0.9% before and after treatment, respectively). The surface area analysis of RHA by BET (Brunauer, Emmett and Teller) nitrogen adsorption method provided pore area and average pore diameter to be 542+/-2.3m(2)g(-1) and 1076+/-5.6nm respectivel...
Source: Colloids and Surfaces - August 20, 2009 Category: Biotechnology Authors: Akhtar M, Iqbal S, Kausar A, Bhanger MI, Shaheen MA Tags: Colloids Surf B Biointerfaces Source Type: journals

From Langmuir-Blodgett films to single molecules.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The author recollects his time in the group of D. Möbius in 1985-1986, within the department headed by Hans Kuhn, and the influence of Kuhn's concept of molecular assembly in the gestation of the first single-molecule experiments. He then briefly surveys the recent applications of single-molecule spectroscopy to complex and heterogeneous systems. In particular the field of single-molecule microscopy in membranes and at biological interfaces is now strongly growing, closing the circle back to Langmuir films, the systems which led to the development of single-molecule optical techniques. PMID: 19726168 [PubMed -...
Source: Colloids and Surfaces - August 17, 2009 Category: Biotechnology Authors: Orrit M Tags: Colloids Surf B Biointerfaces Source Type: journals