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 'Journal of Tissue Engineering and Regenerative Medicine' source. Thu, 09 Feb 2012 16:56:48 +0100 http://www.medworm.com/index.php?rid=5673975&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.526 AbstractStem cells represent an ideal cell source for tissue engineering and regenerative medicine, because they can be readily isolated, expanded, differentiated and transplanted. For stem cell‐based therapies, biomaterials are required to allow for a spatial distribution of the stem cells within a defined area in the body. In our recent studies, we analysed the interaction of a large panel of stem cell types with an array of biomaterials and demonstrated that a rational prediction of stem cell behaviour on a specific biomaterial is so far not possible. Interestingly, even ontogenetically related stem cell types, such as mesenchymal stem cells (MSCs), preadipocytes and dental pulp stem cells (DPSCs), exhibit distinct adhesion properties on the very same biomaterial surface. Therefore, w... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5673975 Thu, 09 Feb 2012 05:00:00 +0100 5673975 http://www.medworm.com/index.php?rid=5673974&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.495 AbstractThe authors previously created HAp or CaCO3 formed on or in agarose gels (HAp and CaCO3 gels, respectively) as biocompatible and biodegradable bone graft materials. However, these gels have limitations for bone regeneration. Mesenchymal stromal cells (MSCs) have osteogenic potential and are considered useful for bone tissue engineering. The purpose of this study was to clarify the osteogenic abilities of MSCs loaded in HAp or CaCO3 gels (MSC/HAp and MSC/CaCO3 gels, respectively) using a rat cranial defect model compared to HAp and CaCO3 gels alone. HAp, CaCO3, MSC/Hap, and MSC/CaCO3 gels were prepared for in vivo analyses and implanted into full‐thickness bone defects created in the rat cranium. All samples were assessed radiologically and histologically at 4 and 8 weeks after ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5673974 Thu, 09 Feb 2012 05:00:00 +0100 5673974 http://www.medworm.com/index.php?rid=5673976&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.528 This study is the first to demonstrate that omentum can provide progenitor cells for repair, thus revealing a novel and naturally occurring source of vascular smooth muscle for use in cell‐based therapies. Furthermore, our data show that this system can be optimized with inducing factors, highlighting a more powerful therapeutic potential than that of its current clinical application. This is a paradigm‐setting concept that lays the foundation for the use of chemical genetics to enhance therapeutic outcomes in a myriad of fields. Copyright © 2012 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5673976 Wed, 08 Feb 2012 05:00:00 +0100 5673976 http://www.medworm.com/index.php?rid=5673977&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.541 In this study, two types of scaffold morphology formed from silk fibroin were investigated towards the goal of AF tissue restoration. The first design mimics the lamellar features of the IVD that are associated with the AF region. The second is a porous spongy scaffold that serves as a control. Toroidal scaffolds were formed from the lamellar and porous silk material systems to generate structures with an outer diameter of 8 mm, inner diameter of 3.5 mm and a height of 3 mm. The inter‐lamellar spacing in the lamellar scaffold was 150–250 µm and the average pore sizes in the porous scaffolds were 100–250 µm. The scaffolds were seeded with porcine AF cells and, after growth over defined time frames in vitro, histology, biochemical assays, mechanical testing and gene express... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5673977 Mon, 06 Feb 2012 05:00:00 +0100 5673977 http://www.medworm.com/index.php?rid=5656518&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.1473 (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5656518 Thu, 02 Feb 2012 05:00:00 +0100 5656518 http://www.medworm.com/index.php?rid=5673973&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.546 We report here on the development and characterization of a cell‐based system for the regulated delivery of bioactive insulin‐like growth factor I (IGF‐I). A stable mammalian cell line, CHO‐K1 Tet‐IGFI, was genetically modified to have tetracycline‐induced transcription of the human IGF‐I gene. Cells were activated to express IGF‐I in the presence of doxycycline (DOX), a tetracycline derivative, while expression was inactivated in the absence of DOX. Temporal, or on‐off, release of IGF‐I from cells encapsulated within Ca2+‐alginate hydrogels was demonstrated in a pilot study over the course of 10 days in culture. Released growth factor was bioactive, exhibiting a proliferative effect comparable to recombinant purified IGF‐I protein. The dosage levels and temporal ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5673973 Wed, 01 Feb 2012 05:00:00 +0100 5673973 http://www.medworm.com/index.php?rid=5656517&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.533 AbstractFor preventing the scar contracture of host tissue and adjusting the tensile strength of covering cell sheets, a controlled collagen crosslinking step process in the preparation of skin‐fibroblast sheets for repairing wound was investigated by using β‐aminopropionitrile (BAPN), a collagen crosslinking inhibitor, in the culture medium. Skin fibroblasts obtained from neonatal rats were cultured in medium with and without 0.25 mm BAPN for 7 days and seeded on temperature‐responsive culture dishes. After the confluent cells were non‐invasively harvested as a monolithic cell sheet, two cell sheets were transplanted to a lung‐injury site of athymic rats, which was closed by neither fibrin glue nor suturing. Four weeks after the transplantation the animals were sacrificed a... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5656517 Wed, 01 Feb 2012 05:00:00 +0100 5656517 http://www.medworm.com/index.php?rid=5643863&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.548 In conclusion, we engineered a fully differentiated human skin trilayer that could present multiple applications such as use for in vitro drug absorption tests and regenerative therapies. Copyright © 2012 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5643863 Tue, 31 Jan 2012 14:49:24 +0100 5643863 http://www.medworm.com/index.php?rid=5643865&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.527 AbstractThis paper is one trial of surface modification of titanium with pronectin F+ (PN) of an artificial protein to enhance gingival adhesion. Titanium plates were electrodeposited in the PN solution to prepare PN‐electrodeposited titanium plates. When PN detachment from the PN‐electrodeposited titanium plates was investigated, no detachment was observed, in contrast to the case of titanium plates simply coated with PN. A cell culture experiment demonstrated that electrodeposited PN had an inherent ability to enhance the initial attachment of gingival epithelial cells. The PN‐electrodeposited titanium plates were implanted between the gingival epithelium and the underlying bone tissue of rabbits to evaluate epithelial growth on the plates and their gingival adhesion. Non‐treated... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5643865 Tue, 31 Jan 2012 05:00:00 +0100 5643865 http://www.medworm.com/index.php?rid=5643864&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.538 AbstractIn tendon rupture repair, improvements such as higher primary repair strength, anti‐adhesion and accelerated healing are needed. We developed a potential carrier system of an electrospun DegraPol® tube, which was tightly implanted around a transected and conventionally sutured rabbit Achilles tendon. Histomorphometric analysis of the tendon tissue 12 weeks postoperation showed that the tenocyte density, tenocyte morphology and number of inflammation zones were statistically equivalent, whether or not DegraPol tube was implanted; only the collagen fibres were slightly less parallelly orientated in the tube‐treated case. Comparison of rabbits that were operated on both hind legs with ones that were operated on only one hind leg showed that there were significantly more inflamm... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5643864 Tue, 31 Jan 2012 05:00:00 +0100 5643864 http://www.medworm.com/index.php?rid=5635466&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.521 This study traced MSCs participating in wound healing by using small intestinal submucosa (SIS) as a cell carrier, identified their moving path and calculated the number of MSCs involved in wound healing. First, MSCs were isolated from the nude mouse and 1 × 106 cells were seeded onto the centre of the SIS. MSC‐seeded SIS complexes were injected onto full‐thickness skin wounds made on the dorsum of nude mice. Tracing of MSC‐seeded SIS complex transplanted to the wound site revealed that 27.6% of the MSCs were migrated to the wound site at the first attempt. Second, repeated injection of additional MSCs did not increase the number of MSCs participating in wound healing beyond a certain constant maximum amount. The number of MSCs present in the wound site remains constant in the r... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5635466 Fri, 27 Jan 2012 21:43:21 +0100 5635466 http://www.medworm.com/index.php?rid=5568912&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.517 We report that the addition of heparin into HA‐based hydrogels provides an attractive surface for EPCs promoting spreading and the formation of an endothelial monolayer on the hydrogel surface. To increase EPC adhesion and spreading, we covalently immobilized CD34 antibody (Ab) on HA–heparin hydrogels, using standard EDC/NHS amine‐coupling strategies. We found that EPC adhesion and spreading on CD34 Ab‐immobilized HA–heparin hydrogels was significantly higher than their non‐modified analogues. Once adhered, EPCs spread and formed an endothelial layer on both non‐modified and CD34 Ab‐modified HA–heparin hydrogels after 3 days of culture. We did not observe significant adhesion and spreading when heparin was not included in the control hydrogels. In addition to EPCs, we a... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5568912 Sun, 01 Jan 2012 05:00:00 +0100 5568912 http://www.medworm.com/index.php?rid=5556792&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.523 In conclusion, this study demonstrates that encapsulation of CSCs in SOD‐loaded alginate hydrogel enhances CSC survival in the presence of DOX, raising the possibility of its application as a novel therapy for the treatment of acute and early onset DOX‐induced cardiotoxicity. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5556792 Fri, 30 Dec 2011 05:00:00 +0100 5556792 http://www.medworm.com/index.php?rid=5501135&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.525 We present the design of our bioreactor and characterize its capability in integrated experimental and mathematical modelling studies. We then cultured cardiac cells obtained from neonatal rats in porous, channelled elastomer scaffolds with the simultaneous application of perfusion and electrical stimulation, with controls excluding either one or both of these two conditions. After 8 days of culture, constructs grown with simultaneous perfusion and electrical stimulation exhibited substantially improved functional properties, as evidenced by a significant increase in contraction amplitude (0.23 ± 0.10% vs 0.14 ± 0.05%, 0.13 ± 0.08% or 0.09 ± 0.02% in control constructs grown without stimulation, without perfusion, or either stimulation or perfusion, respectively). Con... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501135 Tue, 13 Dec 2011 05:00:00 +0100 5501135 http://www.medworm.com/index.php?rid=5501141&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.516 AbstractBone tissue regeneration involves different healing stages and the resulting final hard tissue is formed from natural templates such as fibrous collagen, soft and hard callus and capillary bed. This work aims to evaluate the efficiency of different scaffold geometries with a novel approach: exploring the relationships among scaffold morphologies, cell activity and collagen 3D organization, which serves as a natural template for subsequent mineralization. Among the possible systems to fabricate scaffolds, solvent casting with particulate leaching and microfabrication were used to produce random vs ordered structures from poly( d, l‐lactic acid). In vitro biological testing was carried out by culturing a human osteosarcoma‐derived osteoblast cell line (MG63) and measuring materia... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501141 Mon, 12 Dec 2011 05:00:00 +0100 5501141 http://www.medworm.com/index.php?rid=5501140&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.524 This study compares the influence of 3D pellet culture and alginate beads, as well as that of different media compositions, by the addition of human platelet‐rich plasma (PRP) or transforming growth factor (TGF‐β1) in interaction with hydrostatic pressure on chondrogenic differentiation of human MSCs compared to NP cells. We found that gene expression of the chondrogenic markers aggrecan, collagen type 2 and collagen type 1 and Sox9 was considerably lower in cells cultivated with PRP compared to TGF‐β1. Immunohistology confirmed this result at protein level in pellet culture. Additionally, the pellet culture system was found to be more suitable than alginate beads. A positive influence of hydrostatic pressure could only be shown for individual donors. In summary, in comparison to T... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501140 Mon, 12 Dec 2011 05:00:00 +0100 5501140 http://www.medworm.com/index.php?rid=5501139&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.519 AbstractThis paper describes a non‐invasive approach for efficient detachment of cells adhered to a gold substrate via a specific oligopeptide. Detachment is effected by an electrical stimulus. The oligopeptide contains cysteine, which spontaneously forms a gold–thiolate bond on a gold surface. This chemical adsorption reaches > 95% equilibrium within 10 min after immersion of a gold‐coated substrate in a solution containing the peptide. The peptide is reversibly desorbed from the surface within 5 min of application of a negative electrical potential. By taking advantage of this simple adsorption and desorption mechanism, cells can be grown on an oligopeptide‐functionalized gold surface and can be efficiently detached as single cells or cell sheets by application of a ne... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501139 Mon, 12 Dec 2011 05:00:00 +0100 5501139 http://www.medworm.com/index.php?rid=5501138&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.518 AbstractAlthough many studies using stem cells as therapeutic agents after renal failure have been published in recent years, our knowledge of the factors involved and the cellular mechanisms underlying their beneficial effect on organ regeneration is incomplete. A growing insight into these interactions would help to utilize the biological potential of stem cells for therapeutic approaches. It is here hypothesized that soluble factors released by tubular epithelial cells (TECs) induce epithelial differentiation in adipose‐derived adult mesenchymal stem cells (ASCs). ASCs were therefore cultured in conditioned medium (CM) derived from TECs and the changes in expression genes towards an epithelial pattern were determined by microarray and qPCR analyses. The changes in gene expression were... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501138 Mon, 12 Dec 2011 05:00:00 +0100 5501138 http://www.medworm.com/index.php?rid=5501137&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.522 AbstractMesenchymal cells are central to connective tissue homeostasis and are widely used for tissue‐engineering applications. Dermal fibroblasts and adipose‐derived stromal cells (ASCs) allow successful tissue reconstruction by the self‐assembly approach of tissue engineering. This method leads to the production of multilayered tissues, devoid of exogenous biomaterials, that can be used as stromal compartments for skin or vesical reconstruction. These tissues are formed by combining cell sheets, generated through cell stimulation with ascorbic acid, which favours the cell‐derived production/organization of matrix components. Since media motion can impact on cell behaviour, we investigated the effect of dynamic culture on mesenchymal cells during tissue reconstruction, using the s... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501137 Mon, 12 Dec 2011 05:00:00 +0100 5501137 http://www.medworm.com/index.php?rid=5501136&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.498 This study investigated how human adipose stem cells (hASCs) could be influenced by surface chemistry. Self‐assembled monolayers of alkanethiolates on gold were introduced as a surface chemistry model to provide a range of functional groups such as OH, COOH, NH2, Phenyl, SH, Br, and CH3 on surfaces. Initially, morphological changes of hASCs in response to different surface chemistries were observed with focal adhesion. Cell growth behaviour evaluated by Cell Counting Kit‐8 (CCK8) assay (Dojindo Molecular Technologies Inc., Shanghai, China) and cytoskeletal F‐actin Biochem Kit™ (Denver, CO, USA) staining revealed a descending order of growth rate on the following surfaces: NH2 > SH > COOH > Phenyl > Br > OH > CH3. The mRNA expressions of lin... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501136 Mon, 12 Dec 2011 05:00:00 +0100 5501136 http://www.medworm.com/index.php?rid=5492650&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.497 AbstractBiodegradable porous scaffolds have been investigated as an alternative approach to current metal, ceramic, and polymer bone graft substitutes for lost or damaged bone tissues. Although there have been many studies investigating the effects of scaffold architecture on bone formation, many of these scaffolds were fabricated using conventional methods such as salt leaching and phase separation, and were constructed without designed architecture. To study the effects of both designed architecture and material on bone formation, this study designed and fabricated three types of porous scaffold architecture from two biodegradable materials, poly (L‐lactic acid) (PLLA) and 50:50 Poly(lactic‐co‐glycolic acid) (PLGA), using image based design and indirect solid freeform fabrication t... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5492650 Fri, 09 Dec 2011 05:00:00 +0100 5492650 http://www.medworm.com/index.php?rid=5454094&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.503 AbstractCell therapy strategies that use adult peripheral blood‐derived CD34+ progenitor cells are hampered by low cell numbers and the infrequent cellular incorporation into the neovasculature. Hence, the use of CD34+ cells to treat ischaemic diseases is under debate. Interaction between CD34+ cells and CD14+ cells results in superior endothelial differentiation of CD14+ cells in vitro, indicating that cell therapy approaches utilizing both CD34+ and CD14+ cells may be advantageous in therapeutic neovascularization. Here, human CD34+ and CD14+ cells were isolated from adult peripheral blood and implanted subcutaneously into nude mice, using matrigel as the carrier. Combined implantation of human CD34+ and CD14+ cells resulted in superior neovascularization, compared to either cell type ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5454094 Mon, 28 Nov 2011 05:00:00 +0100 5454094 http://www.medworm.com/index.php?rid=5454093&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.507 In this study we showed that the polymeric structures with controlled architectures produced via 2PP could be used as scaffolds for the in vitro culture and proliferation of human dermal fibroblasts. Fluorescence microscopy revealed that the fibroblasts' orientation was guided by the scaffold geometry, consisting of ormosils lines or grids. This 'dermal equivalent' was investigated for its ability to accommodate epidermal cells. To evaluate this interaction, two experimental approaches were hence used: (a) fibroblast–melanocyte co‐cultures; and (b) fibroblast–keratinocyte organotypic cultures. During their growth on ormosil scaffolds, productive interaction of fibroblasts with both epidermal cell types was found. Moreover, this pseudo‐dermis was shown to support the growth of kerat... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5454093 Mon, 28 Nov 2011 05:00:00 +0100 5454093 http://www.medworm.com/index.php?rid=5428091&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.511 AbstractThe application of tissue engineering (TE) practices for cell delivery offers a unique approach to cellular cardiomyoplasty. We hypothesized that human mesenchymal stem cells (hMSCs) applied to the heart in a collagen matrix would outperform the same cells grown in a monolayer and directly injected for cardiac cell replacement after myocardial infarction in a rat model. When hMSC patches were transplanted to infarcted hearts, several measures for left ventricle (LV) remodelling and function were improved, including fractional area change, wall thickness, –dP/dt and LV end‐diastolic pressure. Neovessel formation throughout the LV infarct wall after hMSC patch treatment increased by 37% when compared to direct injection of hMSCs. This observation was correlated with increased sec... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5428091 Fri, 18 Nov 2011 05:00:00 +0100 5428091 http://www.medworm.com/index.php?rid=5428092&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.487 This study therefore highlighted the challenges involved with nasal reconstruction, with special focus on nasal cartilage tissue, and examined how advancements made in cartilage tissue engineering research could be applied to improve the clinical outcomes of total nasal reconstructive surgery. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5428092 Thu, 17 Nov 2011 05:00:00 +0100 5428092 http://www.medworm.com/index.php?rid=5417669&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.475 AbstractCholesterol‐bearing pullulan (CHP) nanogel is a synthetic degradable biomaterial for drug delivery with high biocompatibility. Guided bone regeneration (GBR) is a bone augmentation technique in which a membrane is used to create and keep a secluded regenerative space. The purpose of the present study was to evaluate the effects of the novel CHP nanogel membrane in GBR. Thirty‐six adult Wistar rats were used and bilaterally symmetrical full‐thickness parietal bone defects of 5 mm diameter were created with a bone trephine burr. Each defect was covered with the collagen membrane or the CHP nanogel membrane or untreated without any membrane. The animals were sacrificed at 2, 4 and 8 weeks and analysed radiologically and histologically. Furthermore, after incubating human ser... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5417669 Thu, 17 Nov 2011 05:00:00 +0100 5417669 http://www.medworm.com/index.php?rid=5417668&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.506 AbstractScaffolds with open‐pore morphologies offer several advantages in cell‐based tissue engineering, but their use is limited by a low cell‐seeding efficiency. We hypothesized that inclusion of a collagen network as filling material within the open‐pore architecture of polycaprolactone–tricalcium phosphate (PCL–TCP) scaffolds increases human bone marrow stromal cells (hBMSCs) seeding efficiency under perfusion and in vivo osteogenic capacity of the resulting constructs. PCL–TCP scaffolds, rapid prototyped with a honeycomb‐like architecture, were filled with a collagen gel and subsequently lyophilized, with or without final crosslinking. Collagen‐free scaffolds were used as controls. The seeding efficiency was assessed after overnight perfusion of expanded hBMSCs direc... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5417668 Thu, 17 Nov 2011 05:00:00 +0100 5417668 http://www.medworm.com/index.php?rid=5404778&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.509 AbstractThe effects of double release of insulin‐like growth factor I (IGF‐I) and growth factor β1 (TGF–β1) from nanoparticles on the growth of bone marrow mesenchymal stem cells and their differentiation into cartilage cells were studied on PLGA scaffolds. The release was achieved by using nanoparticles of poly(lactic acid‐co‐glycolic acid) (PLGA) and poly(N‐isopropylacrylamide) (PNIPAM) carrying IGF‐I and TGF–β1, respectively. On tissue culture polystyrene (TCPS), TGF‐β1 released from PNIPAM nanoparticles was found to have a significant effect on proliferation, while IGF‐I encouraged differentiation, as shown by collagen type II deposition. The study was then conducted on macroporous (pore size 200–400 µm) PLGA scaffolds. It was observed that the combination ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5404778 Mon, 14 Nov 2011 05:00:00 +0100 5404778 http://www.medworm.com/index.php?rid=5404777&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.481 This study reports on the development of chitosan‐collagen scaffolds with micropores and an array of parallel channels (~ 200 µm in diameter) that were specifically designed for cardiac tissue engineering using mechanical stimulation. The scaffolds were designed to have similar structural and mechanical properties of those of native heart matrix. Scaffolds were seeded with neonatal rat heart cells and subjected to dynamic tensile stretch using a custom designed bioreactor. The channels enhanced oxygen transport and facilitated the establishment of cell connections within the construct. The myocardial patches (14 mm in diameter, 1–2 mm thick) consisted of metabolically active cells that began to contract synchronously after 3 days of culture. Mechanical stimulation with high ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5404777 Mon, 14 Nov 2011 05:00:00 +0100 5404777 http://www.medworm.com/index.php?rid=5404776&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.504 This study further evaluated the therapeutic potential of UCM‐MSCs in a mouse Parkinson's disease (PD) model. Differences in expression of some cell surface and cytoplasm specific markers were evident between UCM‐MSCs and BM‐MSCs. However, the expression profile indicated the primitive nature of UCM‐MSCs, along with their less or non‐immunogenic features, compared with BM‐MSCs. In vitro differentiation results showed that BM‐MSCs had a higher tendency to form osteocytes and adipocytes, whereas UCM‐MSCs possessed an increased potential to transform into immature or mature neuron‐like cells. Based on these findings, UCM‐MSCs were transplanted into the right substantia nigra (SN) of a mouse PD model. Transplantation of UCM‐MSCs partially recovered the mouse PD model by s... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5404776 Mon, 14 Nov 2011 05:00:00 +0100 5404776 http://www.medworm.com/index.php?rid=5404775&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.493 This study's primary goal was to develop an effective ex vivo expansion method for haematopoietic cells. 3D culture of mouse bone marrow cells was performed in porous scaffolds using a sheet or cube shape. Bone marrow cells were cultured on bone marrow‐derived stromal layers formed within the scaffolds and the effect of scaffold shape on the expansion of haematopoietic cells was examined. In some experiments, stromal layers within cubic scaffolds were frozen and then used to culture bone marrow cells after thawing. Results show that after comparison, total cell density and expansion of haematopoietic cells were greater in cultures using the cubic scaffold, suggesting that it was superior to the sheet‐like scaffold for expanding haematopoietic cells. When cryopreserved stroma was used, ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5404775 Mon, 14 Nov 2011 05:00:00 +0100 5404775 http://www.medworm.com/index.php?rid=5396839&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.500 This study presents an overview of the use of hydrogels in acellular and cellular strategies for intervertebral disc regeneration. To better understand IVD and its functioning, this study will focus on several aspects: anatomy, pathophysiology, cellular and biomolecular performance, intrinsic healing processes, and current therapies. In addition, the application of hydrogels as NP substitutes will be addressed due to their similarities to NP mechanical properties and extracellular matrix. These hydrogels can be used in cellular strategies when combined with cells from different sources, or in acellular strategies by performing the functionalization of the hydrogels with biomolecules. In addition, a brief summary of therapies based on simple injection for primary biological repair will be e... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5396839 Wed, 09 Nov 2011 05:00:00 +0100 5396839 http://www.medworm.com/index.php?rid=5396838&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.508 AbstractBioprosthetic devices, constructed from a variety of materials, are routinely implanted in a variety of anatomical locations. Essential to their success is the formation of a non‐destructive interface with the host tissue and appropriate tissue remodelling. Traditionally, the main method of assessing the host–material interface has been qualitative histological evaluation, using pattern recognition and comparative assessment to identify changes in the normal tissue architecture that are characteristic of scar tissue. In the present study, the recently developed technique of multispectral imaging was used to revisit a little‐described histological stain, Herovici's polychrome, which is capable of distinguishing between types I and III collagen. Combined, these techniques allow... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5396838 Wed, 09 Nov 2011 05:00:00 +0100 5396838 http://www.medworm.com/index.php?rid=5396837&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.480 ABSTRACTBiological treatment options for the repair of intervertebral disc damage have been suggested for patients with chronic low back pain. The aim of this study was to investigate possible cell types and gel carriers for use in the regenerative treatment of degenerative intervertebral discs (IVD). In vitro: human mesenchymal cells (hMSCs), IVD cells (hDCs), and chondrocytes (hCs) were cultivated in three gel types: hyaluronan gel (Durolane®), hydrogel (Puramatrix®), and tissue‐glue gel (TISSEEL®) in chondrogenic differentiation media for 9 days. Cell proliferation and proteoglycan accumulation were evaluated with microscopy and histology. In vivo: hMSCs or hCs and hyaluronan gel were co‐injected into injured IVDs of six minipigs. Animals were sacrificed at 3 or 6 months. Tra... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5396837 Wed, 09 Nov 2011 05:00:00 +0100 5396837 http://www.medworm.com/index.php?rid=5375473&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.478 AbstractEncased in lacunae, osteocytes receive nutrition and biomechanical signals through the lacunocanalicular system. We have developed a novel flow‐perfusion bioreactor designed to support lacunocanalicular fluid flow. We hypothesize that ex vivo fluid flow can maintain endochondral bone viability and, ultimately, serve as a novel model to study bone biology in vitro. Sprague–Dawley rat femurs were harvested, stripped of soft tissue, loaded into a custom‐designed bioreactor and perfused with osteogenic culture medium. After 14 days of flow‐perfusion or static culture, the bones were harvested, fixed, decalcified, embedded, sectioned and stained with haematoxylin and eosin. Fresh long bone samples were similarly processed for comparison. Osteocyte viability and function were a... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375473 Thu, 03 Nov 2011 04:00:00 +0100 5375473 http://www.medworm.com/index.php?rid=5375472&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.488 This study isolated and characterized cementoblast cells derived from rat molar periodontal ligament. It was observed that the isolated cells expressed F‐Spondin, a cementoblast marker, while F‐Spondin expression was not observed in the cells of other tissues such as gingival fibroblasts and osteoblasts. As expected, the isolated cementoblast cells also expressed osteocalcin (OC), bone sialoprotein (BSP), alkaline phosphatase (ALP), and type I collagen, demonstrating the presence of mineralized tissues genes in cementoblast cells. These cells showed high ALP activity and calcified nodule formation in vitro. Since cementogenesis could be a critical event for regeneration of periodontal tissues, this study investigated whether bioactive glass particles could affect the proliferation of c... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375472 Thu, 03 Nov 2011 04:00:00 +0100 5375472 http://www.medworm.com/index.php?rid=5375471&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.485 This study showed, by means of radioactive isotope methods, that PAAG can exchange both physiological and non‐physiological constituents very efficiently with the surrounding medium. The efflux (J, mole/(cm2 × s), 25 °C, pH 7.2) of water (4.4 × 10−5), chloride (2.4 × 10−7), urea (1.0 × 10−9), and glucose (1.1 × 10−9) was 3‐40x greater than in human red blood cells. PAAG was also accessible to sucrose, inulin, and benzylpenicillin that could not permeate biological cell membranes. The conclusion of the study is that the hydrogel structure created no significant barrier to the exchange of solvent and solutes with the surrounding medium. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375471 Thu, 03 Nov 2011 04:00:00 +0100 5375471 http://www.medworm.com/index.php?rid=5375470&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.490 This study compared the histology and expression of several extracellular matrix molecules in human artificial oral mucosa developed using two different types of scaffolds: fibrin and fibrin‐agarose. To that end, bioengineered oral mucosa stromas were constructed from biopsy samples of human oral mucosa and the substitute generated was analyzed at different periods of time in culture. Histological analysis was carried out by light and transmission electron microscopy and the expression of collagen types I, III, and VI, the proteoglycans decorin and biglycan, and the different chains of laminin, were assessed by immunoperoxidase technique. This study found that fibrin scaffolds accelerated fibroblast growth and remodeling of the scaffold, thus enhancing collagen fibrillogenesis. In the fi... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375470 Thu, 03 Nov 2011 04:00:00 +0100 5375470 http://www.medworm.com/index.php?rid=5375469&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.484 This study reconstructed renal tissues using mixed renal cells in collagen/Matrigel® scaffolds in vitro. Neonatal rat renal cells were seeded in collagen I supplemented with Matrigel in a casting mold that could exert static stretch when the renal constructs contracted. During in vitro culture, the renal constructs were observed under microscope and analyzed by histological and immunofluorescent examinations. Results showed that the mixed renal cells reconstituted renal tubular and glomeruli‐like structures with different appearances at varying developmental stages. Tubular structures were formed by CK18‐positive cells with similar appearances lining the surrounding hollow centres. The glomeruli‐like structures were tufts of cell aggregates containing Flk‐1‐positive cells. These... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375469 Thu, 03 Nov 2011 04:00:00 +0100 5375469 http://www.medworm.com/index.php?rid=5556791&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.520 We describe the properties of hydrogel materials and various techniques used in hydrogel patterning methods. Also, the applicability and utilization of patterned hydrogels with neural cells is discussed. Surface chemistry and topography significantly affect cell behaviour, including cell attachment, migration and maturation. Although several patterning techniques are described in the literature, a review of techniques applicable to hydrogel materials is needed. Use of these patterned cell–hydrogel constructs might provide novel ways to treat central nervous system deficits in the future. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5556791 Tue, 01 Nov 2011 04:00:00 +0100 5556791 http://www.medworm.com/index.php?rid=5501134&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.510 AbstractIn tissue engineering, chemical and topographical cues are normally developed using static cell cultures but then applied directly to tissue cultures in three dimensions (3D) and under perfusion. As human cells are very sensitive to changes in the culture environment, it is essential to evaluate the performance of any such cues in a perfused environment before they are applied to tissue engineering. Thus, the aim of this research was to bridge the gap between static and perfusion cultures by addressing the effect of perfusion on cell cultures within 3D scaffolds. For this we developed a scaled‐down bioreactor system, which allows evaluation of the effectiveness of various chemical and topographical cues incorporated into our previously developed tubular ε‐polycaprolactone scaf... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5501134 Tue, 01 Nov 2011 04:00:00 +0100 5501134 http://www.medworm.com/index.php?rid=5492649&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.469 AbstractMesenchymal stem cells (MSCs) may be among the first stem cell types to be utilized in the clinic for cell therapy, because of their ease of isolation and extensive differentiation potential. Using a porcine model, we have established several cell lines from MSCs to facilitate in vitro and in vivo studies of their potential use for cellular therapy. Bone marrow‐derived primary MSCs were immortalized using the pRNS‐1 plasmid. We obtained four stable immortalized cell lines that exhibited higher proliferative capacities than the parental cells. All four cell lines displayed a common phenotype similar to that of primary mesenchymal cells, characterized by constitutively high expressions of CD90, CD29, CD44, SLA I and CD46, while CD172a, CD106 and CD56 were less expressed. Remarkab... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5492649 Tue, 01 Nov 2011 04:00:00 +0100 5492649 http://www.medworm.com/index.php?rid=5454092&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.494 This study established a method for fluorescent tracking of the degradation of a chitosan membrane scaffold for use in vitro in bioreactors and ultimately in vivo. The basis of this tracking system is a fluorescence emitting biomaterial obtained by covalent binding of the fluorophore tetramethylrhodamine isothiocyanate (TRITC) onto the backbone of chitosan. Using confocal microscopy, this study quantitated the reductions in fluorescence intensity of the membrane and correlated these decreases with weight loss during polymer breakdown, thereby providing a technique for non‐destructively assessing the extent of degradation of chitosan materials over time in vitro. Using multispectral imaging in a mouse model, the study assessed the degradation profile of the fluorophore‐labeled biomateri... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5454092 Tue, 01 Nov 2011 04:00:00 +0100 5454092 http://www.medworm.com/index.php?rid=5447667&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.486 AbstractWe recently showed the fortifying effect of poly‐caprolactone (PCL) scaffold in liquid solder‐mediated laser‐assisted vascular repair (ssLAVR) of porcine carotid arteries, yielding a mean ± SD leaking point pressure of 488 ± 111 mmHg. Despite supraphysiological pressures, the frequency of adhesive failures was indicative of weak bonding at the solder‐tissue interface. As a result, this study aimed to improve adhesive bonding by using a semi‐solid solder and single‐spot vs. scanning irradiation. In the first experiment, in vitro ssLAVR (n = 30) was performed on porcine abdominal aorta strips using a PCL scaffold with a liquid or semi‐solid solder and a 670‐nm diode laser for dual‐pass scanning. In the second experiment, the scanning method was compa... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5447667 Tue, 01 Nov 2011 04:00:00 +0100 5447667 http://www.medworm.com/index.php?rid=5437293&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.502 AbstractChondrogenically differentiating bone marrow‐derived mesenchymal stem cells (BMSCs) display signs of chondrocyte hypertrophy, such as production of collagen type X, MMP13 and alkaline phosphatase (ALPL). For cartilage reconstructions this is undesirable, as terminally differentiated cartilage produced by BMSCs mineralizes when implanted in vivo. Terminal differentiation is not restricted to BMSCs but is also encountered in chondrogenic differentiation of adipose‐derived mesenchymal stem cells (MSCs) as well as embryonic stem cells, which by definition should be able to generate all types of tissues, including stable cartilage. Therefore, we propose that the currently used culture conditions may drive the cells towards terminal differentiation. In this manuscript we aim to revie... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5437293 Tue, 01 Nov 2011 04:00:00 +0100 5437293 http://www.medworm.com/index.php?rid=5428090&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.514 AbstractTo engineer a functional vocal fold tissue, the mechanical environment of the native tissue needs to be emulated in vitro. We have created a dynamic culture system capable of generating vibratory stimulations at human phonation frequencies. The novel device is composed of a function generator, a power amplifier, an enclosed loudspeaker and a circumferentially‐anchored silicone membrane. The vibration signals are translated to the membrane aerodynamically by the oscillating air pressure underneath. The vibration profiles detected on the membrane were symmetrical relative to the centre of the membrane as well as the resting position over the range of frequencies (60–300 Hz) and amplitudes tested (1–30 µm). The oscillatory motion of the membrane gave rise to two orthogonal,... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5428090 Tue, 01 Nov 2011 04:00:00 +0100 5428090 http://www.medworm.com/index.php?rid=5417667&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.505 The objective was to improve proliferation and chondrogenic potential of adipose stem cells (ASCs) by expansion on extracellular matrix (ECM) deposited by either ASCs or synovium‐derived stem cells (SDSCs). ASCs isolated from porcine infrapatellar fat pad were separately expanded on conventional plastic flasks, ASC‐deposited ECM and SDSC‐deposited ECM. ASCs were centrifuged to form pellets and cultured in a serum‐free chondrogenic medium with either TGFβ3 or TGFβ3 combined with BMP‐6. Cell number yielded on ECM expansion did not show a significant difference in deposition between ASCs and SDSCs but was 6–10 times that grown on non‐coated flasks. ECM‐expanded ASCs exhibited a lower level of intracellular reactive oxygen species (ROS) compared to those grown on non‐coated... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5417667 Tue, 01 Nov 2011 04:00:00 +0100 5417667 http://www.medworm.com/index.php?rid=5404774&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.496 AbstractThe availability of autologous articular chondrocytes remains a limiting issue in matrix assisted autologous chondrocyte transplantation. Non‐articular heterotopic chondrocytes could be an alternative autologous cell source. The aims of this study were to establish heterotopic chondrocyte cocultures to analyze cell‐cell compatibilities and to characterize the chondrogenic potential of nasoseptal chondrocytes compared to articular chondrocytes. Primary porcine and human nasoseptal and articular chondrocytes were investigated for extracellular cartilage matrix (ECM) expression in a monolayer culture. 3D polyglycolic acid‐ (PGA) associated porcine heterotopic mono‐ and cocultures were assessed for cell vitality, types II, I, and total collagen‐, and proteoglycan content. The... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5404774 Tue, 01 Nov 2011 04:00:00 +0100 5404774 http://www.medworm.com/index.php?rid=5396836&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.489 This study showed that co‐cultured human bone marrow stem cells (hBMSCs) and periosteal‐derived stem cells (hPCs) resulted in a synergistic effect on osteogenic differentiation both in vitro and in vivo. Compared to hBMSCs and hPCs, co‐culturing MSCs showed abundant mineralization, robust calcium deposition, steadily increasing ALP activity, and upgraded mRNA expression of osteogenic specific genes (COL1A1, BMP‐2, osteopontin, osteocalcin) in vitro. Eight weeks after implantation of cellular β‐TCP scaffolds in immunodeficient mice, similar synergistic effects were confirmed during in vivo evaluation of total new bone formation, mature bone formation, and neovascularization. Based on these findings, the use of co‐cultured hBMSCs and hPCs can be recommended as a promising new ap... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5396836 Tue, 01 Nov 2011 04:00:00 +0100 5396836 http://www.medworm.com/index.php?rid=5375468&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.515 This article is a U.S. Government work and is in the public domain in the USA (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375468 Tue, 01 Nov 2011 04:00:00 +0100 5375468 http://www.medworm.com/index.php?rid=5375478&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.483 This study demonstrated, using autogenic cell transplantation in a porcine model, that DBCs seeded into fibrin glue‐PRF could regenerate a complete tooth. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375478 Fri, 28 Oct 2011 04:00:00 +0100 5375478 http://www.medworm.com/index.php?rid=5375477&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.512 AbstractAngiogenesis plays a key role in post‐ischaemic myocardial repair. We hypothesized that epicardial implantation of an ascorbic acid (AA)‐enriched myocardial artificial graft (MAG), which has been prevascularized in the recipients' own body, promotes restoration of the ischaemic heart. Gelatin patches were seeded with GFP–luciferase‐expressing rat cardiomyoblasts and enriched with 5 μ m AA. Grafts were prevascularized in vivo for 3 days, using a renal pouch model in rats. The MAG patch was then implanted into the same rat's ischaemic heart following myocardial infarction (MI). MAG‐treated animals (MAG group, n = 6) were compared to untreated infarcted animals as injury controls (MI group, n = 6) and sham‐operated rats as healthy controls (healthy group, n =�... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375477 Fri, 28 Oct 2011 04:00:00 +0100 5375477 http://www.medworm.com/index.php?rid=5375476&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.492 This study showed that CG scaffolds crosslinked by EDC and seeded with human fibroblasts could serve as dermal constructs, while the bioglue coating seeded with keratinocytes could serve as an epidermal construct. Such a combination could help regenerate skin with integrated dermal and epidermal layers and a have potential use in tissue‐engineered skin. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375476 Fri, 28 Oct 2011 04:00:00 +0100 5375476 http://www.medworm.com/index.php?rid=5375475&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.501 AbstractCells actively probe the stiffness of their surrounding and respond to it. The authors recently found that maintenance of the chondrogenic phenotype was directly influenced by this property in 2D. Since studies about this process in 3D are still largely absent, this study aimed to transfer this knowledge into a 3D environment. Agarose was modified with RGD to allow active stiffness sensing or RGE as a control. Hydrogels with different mechanical properties were produced by using different concentrations of agarose. Primary chondrocytes were incorporated into the gel, cultured for up to two weeks, and then constructs were analyzed. Cells were surrounded by their own ECM from an early stage and maintained their chondrogenic phenotype, independent of substrate composition, as indicate... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375475 Fri, 28 Oct 2011 04:00:00 +0100 5375475 http://www.medworm.com/index.php?rid=5375474&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.491 In conclusion, this study showed that the PCL/PVPA scaffold is a novel system that has the potential for use as a bone graft substitute and in assisting in the healing of critical size defects. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5375474 Fri, 28 Oct 2011 04:00:00 +0100 5375474 http://www.medworm.com/index.php?rid=5246363&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.470 This study demonstrated that aligned electrospun fibres guide cell alignment, induce a more elongated cell morphology and promote a more synthetic phenotype. Importantly, these cells produced greater amounts of elastin‐rich matrix per cell on the electrospun scaffolds. In addition, exogenous elastogenic factors severely limited rat aortic smooth muscle cells (RASMCs) proliferation and promoted a more synthetic SMC phenotype on electrospun meshes, but they had less effect on 2D controls. Finally, the elastogenic factors induced the SMCs to generate more matrix collagen and elastin on a per cell basis. Together, these results demonstrate the elastogenic benefits of electrospun meshes. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medi... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246363 Fri, 23 Sep 2011 10:37:26 +0100 5246363 http://www.medworm.com/index.php?rid=5246367&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.477 In this study we investigated whether the presence of collagen type I or II in gel lattices affects matrix contraction and relative gene expression levels of matrix proteins, MMPs and the subsequent degradation of collagen by goat articular chondrocytes. Only floating collagen I gels, and not those attached or composed of type II collagen, contracted during a culture period of 12 days. This coincided with an upregulation of both Mmp13 and −14 gene expression, whereas Mmp1 expression was not affected. The release of hydroxyproline in the culture medium, indicating matrix degradation, was increased five‐fold in contracted collagen I gels compared to collagen II gels without contraction. Furthermore, blocking contraction of collagen I gels by cytochalasin B inhibited Mmp13 and −14 exp... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246367 Thu, 22 Sep 2011 04:00:00 +0100 5246367 http://www.medworm.com/index.php?rid=5246366&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.465 AbstractThe aim of this work was to isolate, for the first time, progenitor‐like cells from the epithelial (AECs) and mesenchymal (AMCs) portions of the horse amniotic membrane, and to define the biological properties of these cells. AECs displayed polygonal epithelial morphology, while AMCs were fibroblast‐like. Usually, six to eight passages were reached before proliferation decreased, with 13.08 and 26.5 cell population doublings attained after 31 days for AECs and AMCs, respectively. Immunocytochemical studies performed at passage 3 (P3) showed that both cell populations were positive for the expression of specific embryonic markers (TRA‐1‐60, SSEA‐3, SSEA‐4 and Oct‐4). Meanwhile, RT–PCR performed at P1 and P5 showed expression of mesenchymal stem/stromal cell markers... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246366 Thu, 22 Sep 2011 04:00:00 +0100 5246366 http://www.medworm.com/index.php?rid=5246365&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.476 In this study, a novel automated cell‐seeding device utilizing direct cell deposition, patterning techniques and scaffold rotation was designed to improve the cell viability, uniformity and seeding efficiency of tubular constructs. Quantification methods and imaging techniques were used to evaluate these parameters on the luminal and abluminal sides of fibrous polymer scaffolds. With the automated seeding method, a high cell‐seeding efficiency (~89%), viability (~85%) and uniformity (~85–92%) were achieved for both aortic smooth muscle cells (AoSMCs) and aortic endothelial cells (AoECs). The duration of the seeding process was < 8 min. Initial cell density, cell suspension in matrix‐containing media, duration of seeding process and scaffold rotation were found to affect th... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246365 Thu, 22 Sep 2011 04:00:00 +0100 5246365 http://www.medworm.com/index.php?rid=5246364&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.474 AbstractRupture of the anterior cruciate ligament (ACL) is the one of the most common sports‐related injuries. With its poor healing capacity, surgical reconstruction using either autografts or allografts is currently required to restore function. However, serious complications are associated with graft reconstructions and the number of such reconstructions has steadily risen over the years, necessitating the search for an alternative approach to ACL repair. Such an approach may likely be tissue engineering. Recent engineering approaches using ligament‐derived fibroblasts have been promising, but the slow growth rate of such fibroblasts in vitro may limit their practical application. More promising results are being achieved using bone marrow mesenchymal stem cells (MSCs). The adipose�... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246364 Thu, 22 Sep 2011 04:00:00 +0100 5246364 http://www.medworm.com/index.php?rid=5246371&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.467 AbstractTo better understand the use of Schwann cells (SCs) and bone marrow stromal cells (BMSCs) together for nerve repair, we studied whether interactions between these two cell types by diffusible molecules can enhance their utility. In the present study, a co‐culture system was established to allow BMSCs and SCs grow in the same culture medium but without physical contact. Before co‐culture, the adult SCs were expanded until confluent. The adult BMSCs were cultured until P10 with CD29 and CD44 positive but CD45 negative. After 4 days in culture, > 80% of the BMSCs in the co‐culture system showed both GFAP‐ and S‐100‐positive, but < 6% of the BMSCs in control culture system showed both GFAP‐ and S‐100‐positive. Meanwhile, 68.76% of the SCs in co‐culture s... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246371 Tue, 20 Sep 2011 04:00:00 +0100 5246371 http://www.medworm.com/index.php?rid=5246370&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.472 In conclusion, TGFβ1–HOB loaded PCL can be applied to create a model for total atherosclerotic occlusion with cell‐deposited calcium in animal arteries. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246370 Tue, 20 Sep 2011 04:00:00 +0100 5246370 http://www.medworm.com/index.php?rid=5246369&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.473 In this study we aimed to determine whether on‐line measurements of oxygen can be used as a non‐destructive method to estimate the number of chondrocytes within an engineered cartilage graft. Human chondrocytes were seeded and cultured in a perfusion bioreactor, and oxygen levels in the culture medium were continuously monitored at the inlet and outlet of the bioreactor chamber throughout the culture period. We found that the drop in oxygen across the perfused construct was linearly correlated with the number of cells per construct (R2 = 0.82, p < 0.0001). The method was valid for a wide range of cell numbers, including cell densities currently used in the manufacture of cartilage grafts for clinical applications. Given that few or no non‐destructive assays that quantitati... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246369 Tue, 20 Sep 2011 04:00:00 +0100 5246369 http://www.medworm.com/index.php?rid=5246368&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.482 AbstractMany cell therapy approaches aim to deliver high‐density single‐cell suspensions to diseased or injured sites in the body. Long term clinical success will in part be dependent on the cells that remain viable and that assume correct functionality post‐administration. The research presented in this paper focuses on the potential of cell aggregate delivery to generate a more supportive environment for cells than single cell suspensions. An in vitro model of injection delivery of C2C12 myoblast cells showed a significant difference in cell function and phenotype between adhesive collagen and non‐adhesive alginate, indicating that in vitro assays based on this approach can discriminate between cell‐cell/cell‐matrix interactions and could be valuable when assessing cell thera... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5246368 Tue, 20 Sep 2011 04:00:00 +0100 5246368 http://www.medworm.com/index.php?rid=5217712&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.464 AbstractApart from soluble growth factors, various other biophysicochemical cues are known to promote chondrogenesis. Under physiological conditions, cartilage in the joint comprises a hyperosmotic and hypoxic environment. Therefore, in this study, we examined the inductive effects of hyperosmotic and/or hypoxic conditions on adipose stem cells (ASCs) and compared them with conventional TGFβ1‐induction. After encapsulation in collagen type II hydrogels and specific induction, ASCs were assessed for viability, proliferation, morphology and chondrogenic differentiation potential. Viability was similar under all conditions, with low proliferative activity. After 4 days, hypoxia and/or hyperosmolarity did not affect round cell morphology, while cells were mainly stretched in the TGFβ1‐... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217712 Tue, 13 Sep 2011 04:00:00 +0100 5217712 http://www.medworm.com/index.php?rid=5217711&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.461 AbstractThe most critical factor for fracture union is the blood supply to the fracture site, which is usually impaired in patients with diabetes. Recently, mesenchymal stem cells‐derived conditioned medium (MSC‐CM) has shown significantly higher levels of angiogenic factors, such as VEGF and IL‐6. We demonstrate in this report that MSC‐CM delivered in gelatin sponges stimulates angiogenesis and promotes fracture healing in a diabetic rat model. Subcutaneous implantation of gelatin sponges soaked in MSC‐CM demonstrated better tissue ingrowth and higher capillary densities at 2 and 3 weeks than gelatin sponges soaked in minimal essential medium (MEM) or 293 cell‐derived conditioned medium (293‐CM). Implantation of fibular defects with gelatin sponges soaked in MSC‐CM enhan... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217711 Tue, 13 Sep 2011 04:00:00 +0100 5217711 http://www.medworm.com/index.php?rid=5217710&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.458 AbstractTo disclose the influence of foreign body responses raised against a non‐absorbable hydrogel consisting of tissue‐engineered cartilage, we embedded human/canine chondrocytes within agarose and transplanted them into subcutaneous pockets in nude mice and donor beagles. One month after transplantation, cartilage formation was observed in the experiments using human chondrocytes in nude mice. No significant invasion of blood cells was noted in the areas where the cartilage was newly formed. Around the tissue‐engineered cartilage, agarose fragments, a dense fibrous connective tissue and many macrophages were observed. On the other hand, no cartilage tissue was detected in the autologous transplantation of canine chondrocytes. Few surviving chondrocytes were observed in the agaros... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217710 Tue, 13 Sep 2011 04:00:00 +0100 5217710 http://www.medworm.com/index.php?rid=5217709&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.468 In this study, we hoped to determine whether hUC‐MSCs could be induced to differentiate into sweat gland cell‐like cells, that would be potential in sweat glands restoration after injury. In this study, the results of flow cytometry analysis revealed that hUC‐MSCs showed the typical antigen profile of MSCs and were positive for CD29, CD44, CD90, CD105 and Oct‐4; they were negative for the antigens of CD34, CEA and CK14. Remarkably, hUC‐MSCs maintained proper proliferation and differentiation ability. After culture in sweat gland cell‐conditioned medium (induction group 1) for 3 weeks, hUC‐MSCs possessed sweat gland cell‐like morphology and expressed markers of sweat gland cells (CEA, CK14 and CK19) more efficiently than those of induction group 2. In reverse‐transcripti... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217709 Tue, 13 Sep 2011 04:00:00 +0100 5217709 http://www.medworm.com/index.php?rid=5217708&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.463 The objective of the present study was to enhance the regeneration ability of an injectable bone regeneration composite (IBRC) by the controlled release of recombinant human bone morphogenetic protein‐2 (rhBMP‐2). The IBRC comprised nano‐hydroxyapatite/collagen (nHAC) particles in an alginate hydrogel carrier. First, bovine serum albumin (BSA) as a model protein was released from IBRC to evaluate its release rules. The results suggested that IBRC is a good controlled release carrier for BSA in the range 5–75 µg/ml. In the in vitro study the rhBMP‐2 released from IBRC was determined by an enzyme‐linked immunosorbent assay specific for rhBMP‐2. The bioactivity of the released rhBMP‐2 was evaluated through differentiated function of marrow mesenchymal stem cells (MSCs), as ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217708 Tue, 13 Sep 2011 04:00:00 +0100 5217708 http://www.medworm.com/index.php?rid=5094322&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.460 AbstractTissue‐engineered medical products (TEMPs) should be evaluated before implantation. Therefore, it is indispensable to establish evaluation protocols in regenerative medicine. Whether or not such evaluation protocols are reasonable is generally verified through a 'round robin' test. However, the round robin test for TEMPs intrinsically includes a deficiency, because 'identical' specimens can not be prepared for TEMPs. The aim of the study was to assess the feasibility and limitations of the round robin test for TEMPs by using a prepared evaluation protocol. We adopted tissue‐engineered cartilage constructs as delivered specimens and a protocol of measuring sGAG content as an evaluation protocol proposed to ISO TC150/SC7, which is an invasive, but usually applied, method, althoug... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5094322 Mon, 01 Aug 2011 23:00:00 +0100 5094322 http://www.medworm.com/index.php?rid=5094318&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.455 AbstractThe use of extracellular matrix (ECM) molecules from tissues is an interesting way to induce specific responses of cells grown onto composite scaffolds to promote adhesion, proliferation and differentiation. There have been several studies on the effects on cell proliferation and differentiation of osteoprogenitor cells cultured onto composites, either adding some ECM molecules or grown in the presence of growth factors. Other studies involve the use of osteoblasts cultured on a three‐dimensional (3D) matrix, enriched with ECM molecules produced by the same cells grown previously inside the composite. Here, the effect of enrichment of a novel multilayered chitosan–hydroxyapatite composite with ECM molecules produced by osteoblasts, or the addition of 25 or 50 µg/ml fibronectin... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5094318 Mon, 01 Aug 2011 23:00:00 +0100 5094318 http://www.medworm.com/index.php?rid=5217707&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.466 AbstractIn regenerative medicine, the generation of biocompatible substitutes of tissues by in vitro tissue engineering must fulfil certain requirements. In the case of human oral mucosa, the rheological properties of tissues deserve special attention because of their influence in the acoustics and biomechanics of voice production. This work is devoted to the rheological characterization of substitutes of the connective tissue of the human oral mucosa. Two substitutes, composed of fibrin and fibrin–agarose, were prepared in cell culture for periods in the range 1–21 days. The time evolution of the rheological properties of both substitutes was studied by two different experimental procedures: steady‐state and oscillatory measurements. The former allows the plastic behaviour of the ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5217707 Mon, 01 Aug 2011 04:00:00 +0100 5217707 http://www.medworm.com/index.php?rid=5094316&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.446 This study evaluated the suitability of adipose‐derived stem cells (ASCs) combined with fibrin matrix of variable composition for adipose tissue‐equivalent formation in vitro. Therefore, undifferentiated ASCs were embedded in fibrin clots composed of 2 IU/ml thrombin and fibrinogen of varying concentrations (6.25, 12.5 and 25 mg/ml) and kept under control or adipogenic conditions. Fibrin–cell composites were evaluated by scanning electron microscopy, live/dead staining, lactate‐dehydrogenase (LDH) assay, quantitative PCR for the adipogenic markers fatty acid binding protein 4 (FABP4), peroxisome proliferative activated receptor‐γ (PPARγ) and leptin, leptin ELISA and oil red O staining. Cells were found homogeneously distributed throughout the clot. Their number increased to day... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5094316 Sun, 31 Jul 2011 23:00:00 +0100 5094316 http://www.medworm.com/index.php?rid=5076407&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.456 In conclusion, the transported autogenous bone particles accelerated peri‐implant osteogenesis. Clinical studies are needed to evaluate the potential of this procedure in clinical practice. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5076407 Sat, 30 Jul 2011 01:22:05 +0100 5076407 http://www.medworm.com/index.php?rid=5076411&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.443 AbstractThe purpose of the current study was to investigate whether the cryopolymerization technique is capable of producing suitable scaffolds for bone tissue engineering. Cryopolymers made of 2‐hydroxyethyl methacrylate and acrylic acid with (W1 and W20) and without (W0) wollastonite particles were prepared. The elastic modulus of the specimens rose one order of magnitude from W1 to W20. Total porosity reached 56% for W0, 72% for W1 and 36% for W20, with pore sizes of up to 2 mm, large interconnection sizes of up to 1 mm and small interconnection sizes of 50–80 µm on dry specimens. Cryogels swell up to 224 ± 17% for W0, 315 ± 18% for W1 and 231 ± 27% for W20 specimens, while maintaining the integrity of the bodies. Pore sizes > 5 mm can be observed for swollen specimens. The b... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5076411 Thu, 28 Jul 2011 23:00:00 +0100 5076411 http://www.medworm.com/index.php?rid=5076410&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.449 In this study, tubular scaffolds made of biodegradable poly(ε‐caprolactone) (PCL) with biomimetic fibrin‐based coating were evaluated to compare the effects of pore sizes on surface coverage of ECs and synthesis of ECM under dynamic culture conditions. Actin was stained for identification of cells, while specific antibodies were used for locating collagen IV and elastin deposition on the scaffolds. It was found that dynamic seeding of ECs in the lumen stabilized the cells and aligned them along the direction of flow, with better deposition of insoluble elastin and collagen IV when ∼75% of pores were < 24 µm in diameter. In addition, monolayer on the ε‐PCL scaffolds with lower pore sizes was found to produce nitric oxide (NO), indicating a non‐thrombogenic EC layer in the lu... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5076410 Thu, 28 Jul 2011 23:00:00 +0100 5076410 http://www.medworm.com/index.php?rid=5076409&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.457 AbstractMost studies on the intervertebral disc (IVD) focus on the regeneration of the nucleus pulposus (NP). However, without a proper strategy to regenerate the damaged annulus fibrosus (AF), the NP replacements are bound to fail. Therefore the objective of this study was to investigate whether the use of bone marrow‐derived mesenchymal stem cells (BMSCs) to form cell sheets, and incorporating them onto silk scaffolds, has the potential to regenerate the annulus fibrosus. The BMSC cell sheets and silk scaffolds were wrapped around a silicone NP substitute to form a simulated IVD‐like assembly. The simulated IVD‐like assembly was cultured for 4 weeks in static conditions and it was shown that the BMSC cell sheets remained viable, with no significant change in cell numbers. Histolo... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5076409 Thu, 28 Jul 2011 23:00:00 +0100 5076409 http://www.medworm.com/index.php?rid=5076408&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.459 In this study, the use of poly(l,d‐lactide) (PLDLA) nanofibre coatings on PLDLA microfibres or films (nanofibre composites) to influence bovine chondrocyte behaviour was investigated. It was demonstrated that electrospun nanofibres facilitated the adhesion of chondrocytes and helped to maintain smaller projected cell areas and a rounded cell phenotype, when compared to PLDLA films or microfibres. Random nanofibre composites were associated with the smallest and most rounded cells and aligned nanofibre composites also demonstrated a similar tendency. Quantitative PCR revealed that nanofibres promoted the expression of chondrogenic markers, such as collagen type IIaI and aggrecan, while maintaining low levels of collagen IaI. It was also found, by water contact angle measurement, that nano... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5076408 Thu, 28 Jul 2011 23:00:00 +0100 5076408 http://www.medworm.com/index.php?rid=5026869&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.451 AbstractSmooth muscle cells (SMCs) are typically used as a cell source for the reconstruction of hollow organs by conventional tissue engineering techniques. However, the necessity for and advantage of the use of tissue‐specific SMCs are unknown. The present study investigated the phenotypic changes that occur following isolation and in vitro expansion of rat SMC populations isolated from three different tissues: the aorta, oesophagus and urinary bladder. rSMCs were isolated by enzymatic dispersion and expanded by conventional cell culture techniques, yielding microscopically homogeneous populations. SMC phenotypes were monitored according to their expression of marker proteins during the first two passages. Two of the three SMC populations (rSMC‐a and rSMC‐e) showed a marked change ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026869 Wed, 13 Jul 2011 23:00:00 +0100 5026869 http://www.medworm.com/index.php?rid=5026883&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.447 This study investigated an alternative gene delivery vector, baculovirus, for the expression of hTERT in primary human cells. A recombinant baculovirus was used to efficiently deliver the hTERT gene to primary fibroblasts and the telomerase enzyme was found to be active. Although no increase in telomere length was detected, expression of hTERT in primary fibroblasts resulted in a significant extension of replicative lifespan. To our knowledge this is a novel attempt to use a recombinant baculovirus for the extension of cellular lifespan by exogenous expression of telomerase. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026883 Tue, 12 Jul 2011 23:00:00 +0100 5026883 http://www.medworm.com/index.php?rid=5026879&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.452 This study investigated the effects of ischaemia (metabolically induced by sodium azide and 2‐deoxyglucose) and serum‐derived mitogens on the viability and functional profile of MSCs in vitro. MSCs were more susceptible to combined, rather than individual, blockade of glycolysis and oxidative phosphorylation. Apoptosis and autophagy were involved in ischaemia‐induced cell death. Chemical ischaemia alone and serum withdrawal alone induced a similar amount of cell death, with significantly different intracellular ATP maintenance. Combined ischaemia and serum deprivation had additive effects on cell death. Expression of the extracellular matrix (ECM) molecules laminin and fibronectin was attenuated under ischaemia and independent of serum level; however, BDNF and NGF levels remained rel... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026879 Tue, 12 Jul 2011 23:00:00 +0100 5026879 http://www.medworm.com/index.php?rid=5026874&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.453 AbstractLittle is known about how cells respond to different biomaterials at the molecular level. Biomaterials could stimulate specific cellular responses at the molecular level, such as activation of signalling pathways that control gene activity involved in the maintenance, growth and functional regeneration of liver tissue in vitro. This aspect is an important step in liver tissue engineering. Currently, there are no data available concerning the modulation of cellular genomic response by using synthetic membranes in a bioartificial system. For the first time we investigated gene expression profiles of primary hepatocytes cultured on different substrates: collagen sandwich, native and NH3 plasma‐grafted PEEK–WC–PU membranes. Gene expression in cell suspension prepared after cell i... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026874 Tue, 12 Jul 2011 23:00:00 +0100 5026874 http://www.medworm.com/index.php?rid=5026889&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.445 AbstractSpinal fusion is routinely performed to treat low back pain caused by degeneration of intervertebral discs. An autologous bone graft derived from the iliac crest is the standard procedure used for spinal fusion. However, several shortcomings, including pseudarthrosis, pain and the need for blood transfusion are known to be associated with the procedure. Our study analysed the effectiveness of a new mineralized collagen matrix, nano‐hydroxyapatite–collagen–polylactic acid (nHAC–PLA), combined with autologous adipose‐derived mesenchymal stem cells (ADMSCs) as a graft material for posterolateral spinal fusion in a rabbit model. Forty rabbits were randomly divided into four groups: autologous iliac crest bone group (ACB), nHAC–PLA composite group (nHAC–PLA), autologous il... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026889 Mon, 11 Jul 2011 23:00:00 +0100 5026889 http://www.medworm.com/index.php?rid=5026887&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.448 In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3 months after glucocorticoid cessation, suggesting a delayed effect of glucocorticoid on cortical bone. Thus, changes in cortical bone beyond cancellous bone might further increase fracture risk in patients treated with glucocorticoids. This model might be used as a glucocorticoid‐induced osteoporotic model for orthopaedic biomaterial, joint prosthesis and medical device researches. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026887 Mon, 11 Jul 2011 23:00:00 +0100 5026887 http://www.medworm.com/index.php?rid=5102773&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.444 AbstractThe following article from the Journal of Tissue Engineering and Regenerative Medicine, ‘Effects of Pro‐inflammatory Cytokines on Mineralization Potential of Rat Dental Pulp Stem Cells’ by Yang X, Walboomers XF, Bian Z, Jansen JA, Fan M, published online on 11 July 2011 in Wiley Online Library (onlinelibrary.wiley.com), has been retracted by agreement between the authors, the journal Editor‐in‐Chief, and John Wiley & Sons, Ltd. The retraction has been agreed due to two authors (Walboomers XF, and Jansen JA) not having been involved in the research described, nor made aware of their names being listed on the manuscript, nor told of its submission to the journal. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5102773 Sun, 10 Jul 2011 23:00:00 +0100 5102773 http://www.medworm.com/index.php?rid=5017860&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.441 AbstractHuman mesenchymal stem cells (hMSCs) are typically obtained for research or therapeutic applications by isolating and subculturing adherent cells from bone marrow on tissue‐culture substrates using growth media. The purity and properties of the resulting populations can be affected greatly by the conditions under which they are cultured. Fetal bovine serum (FBS), although ill‐defined, has been widely used as a critical requirement for conventional hMSC culture. However, a defined serum‐free medium would greatly facilitate the development of robust, clinically acceptable bioprocesses for reproducibly generating quality‐assured cells. The present study provides evidence demonstrating that a defined serum‐free medium (PPRF‐msc6) shows several beneficial features over a con... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5017860 Sun, 10 Jul 2011 23:00:00 +0100 5017860 http://www.medworm.com/index.php?rid=5017859&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.442 In conclusion, we demonstrated that PCLF delivered biologically active rhBMP‐2, promoted bone healing in a CSD and has potential as a bone tissue engineering scaffold. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5017859 Sun, 10 Jul 2011 23:00:00 +0100 5017859 http://www.medworm.com/index.php?rid=5035422&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.450 In this study, we demonstrate that stirred suspension bioreactors yield 58‐fold expansion of undifferentiated pluripotent iPSCs over 4 days. In vitro differentiation into cartilage, bone and cardiomyocytes lineages, in addition to in vivo teratoma formation, further confirmed the existence of fully functional and undifferentiated pluripotent iPSC aggregates following long‐term passaging. Stirred suspension bioreactor culture represents an efficient process for the large‐scale expansion and maintenance of iPSCs, which is an important first step in their clinical application. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5035422 Thu, 30 Jun 2011 23:00:00 +0100 5035422 http://www.medworm.com/index.php?rid=5026863&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.454 This study demonstrates that adipose tissue is an excellent source of autologous endothelial cells to reconstruct endothelialized tissue equivalents, and that pre‐differentiation of stem cells is necessary to obtain vasculature in such models. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5026863 Thu, 30 Jun 2011 23:00:00 +0100 5026863 http://www.medworm.com/index.php?rid=5017858&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.444 In this study, the effects of pro‐inflammatory cytokines, such as IL‐1 and TNF, on DPSCs were investigated. Cells were treated with IL‐1, TNF or both for 3, 7 and 12 days. The cultures were evaluated for cell proliferation and ALP activity and by real‐time PCR. We found that a short treatment (3 days) of pro‐inflammatory cytokines induced the odontogenic differentiation of DPSCs. After 3 days of treatment with pro‐inflammatory cytokines, the cell–scaffold complexes were implanted subcutaneously in mice for 8 weeks. Histological analysis demonstrated that the cultures gave obviously mineralized tissue formation, especially when both IL‐1 and TNF were applied. These data suggest that IL‐1 and TNF produced in the early inflammatory reaction may induce the mineralization of D... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=5017858 Thu, 30 Jun 2011 23:00:00 +0100 5017858 http://www.medworm.com/index.php?rid=4983310&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.437 AbstractThe development of a new generation of multifunctional biomaterials is a continual goal for the field of materials science. The in vivo functional behaviour of a new fusion protein that combines the mechanical properties of spider silk with the antimicrobial properties of hepcidin was addressed in this study. This new chimeric protein, termed 6mer + hepcidin, fuses spider dragline consensus sequences (6mer) and the antimicrobial peptide hepcidin, as we have recently described, with retention of bactericidal activity and low cytotoxicity. In the present study, mouse subcutaneous implants were studied to access the in vivo biological response to 6mer + hepcidin, which were compared with controls of silk alone (6mer), polylactic–glycolic acid (PLGA) films and empty defects. Along wi... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4983310 Thu, 30 Jun 2011 05:44:18 +0100 4983310 http://www.medworm.com/index.php?rid=4974680&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.440 In conclusion, adipose tissue may represent a promising autologous cell source for the development of novel bone regenerative therapeutic strategies in the treatment of age‐related osteoporosis. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974680 Tue, 28 Jun 2011 18:32:58 +0100 4974680 http://www.medworm.com/index.php?rid=4974682&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.436 AbstractProgress in medicine over recent decades has notably increased life expectancy in the Western world. Such advance implies that the treatment of degenerative processes associated with ageing has become one of the major tasks of current medicine and therapeutics. High expectation relies on stem cell research in order to apply cell therapies to ameliorate degenerative processes, remarkably those concerning the circulatory, locomotor and nervous systems. However, the skeletal connective tissues have revealed that cell plasticity is a factor of major importance in regenerative therapies. Most evidence indicates that connective tissue cells of cartilage, tendons, ligaments and fascia share common progenitors during their differentiation, which are regulated by a number of director genes ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974682 Mon, 27 Jun 2011 23:00:00 +0100 4974682 http://www.medworm.com/index.php?rid=4974681&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.439 AbstractThe transplantation of human bone marrow stromal cells (BMSCs) is a novel immunotherapeutic approach that is currently being explored in many clinical settings. Evidence suggests that the efficacy of cell transplantation is directly associated with soluble factors released by human BMSCs. In order to harness these secreted factors, we integrated BMSCs into large‐scale hollow‐fibre bioreactor devices in which the cells, separated by a semipermeable polyethersulphone (PES) membrane, can directly and continuously release therapeutic factors into the blood stream. BMSCs were found to be rapidly adherent and exhibited long‐term viability on PES fibres. The cells also preserved their immunophenotype under physiological fluid flow rates in the bioreactor, and exhibited no signs of d... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974681 Mon, 27 Jun 2011 23:00:00 +0100 4974681 http://www.medworm.com/index.php?rid=4974687&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.428 AbstractBone marrow‐derived mesenchymal stem cells (BMSCs) and adipose tissue‐derived mesenchymal stem cells (AMSCs) have been used clinically for tissue regeneration; however, their proliferation/differentiation potentials are limited. Recently, induced pluripotent stem cells (iPSCs), known to have nearly unlimited potential to proliferate and differentiate into cells of all three germ layers, have gained wide interest in regenerative medicine. Here, we generated iPSCs from frozen‐stocked AMSCs and BMSCs and examined their biological characteristics by comparative analyses. Although the iPSCs were more challenging to generate from the BMSCs than the AMSCs, both iPSC populations expressed pluripotent markers, such as stage‐specific embryonic antigen (SSEA)‐3, SSEA‐4, tumour‐r... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974687 Sun, 26 Jun 2011 23:00:00 +0100 4974687 http://www.medworm.com/index.php?rid=4974686&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.431 In this study, such a PVA system, with DMSO as the cryoprotectant, was successfully developed. Vascular smooth muscle cell (vSMC)‐encapsulated cryogels were investigated under conditions of cyclic strain and in co‐culture with vascular endothelial cells to mimic the environment these cells experience in vivo in a vascular tissue‐engineering setting. In view of the cytotoxicity DMSO imposes with respect to the production procedure, carboxylated poly‐L‐lysine (COOH–PLL) was substituted as a non‐cytotoxic cryoprotectant to allow longer, slower thawing periods to generate more stable cryogels. Encapsulated vSMC with DMSO as a cryoprotectant responded to 10% cyclic strain with increased alignment and proliferation. Cells were stored frozen for 1 month without loss of viability com... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974686 Sun, 26 Jun 2011 23:00:00 +0100 4974686 http://www.medworm.com/index.php?rid=4974685&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.432 AbstractTo treat large bone defects is a clinically challenging problem and utilizing tissue engineering technology is an attractive approach for overcoming such a problem. Previously, a biodegradable sponge incorporating bone morphogenic protein‐2 (BMP‐2), which can control the release of BMP‐2 for a prolonged time in an in vivo environment, was reported. In addition, a biodegradable sponge composed of gelatin and β‐tricalcium phosphate (βTCP), gelatin‐βTCP sponge to develop a more ideal scaffold for enhancing bone regeneration was also created and previously reported. The purpose of this study was to investigate the effectiveness of the gelatin‐βTCP sponge for the promotion of bone regeneration in a critical‐sized bone defect site in vivo. Apparent bone regeneration was... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974685 Sun, 26 Jun 2011 23:00:00 +0100 4974685 http://www.medworm.com/index.php?rid=4974684&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.434 This study focused on the development of new polymeric membranes in flat and tubular (hollow‐fibre) configurations as novel biomaterials for neuronal outgrowth. Two membrane systems constituted by modified polyetheretherketone (PEEK‐WC) and polyacrylonitrile (PAN) membranes were developed and used for the culture of hamster hippocampal neurons. We demonstrated that all investigated membranes supported the adhesion and growth of hippocampal neurons enhancing neuronal differentiation and neurite alignment. The differences in cell behaviours between cells cultured on flat and hollow‐fibre (HF) membranes were highlighted by the quantitative analysis of neuronal marker fluorescence intensity, morphometric analysis, RT–PCR analysis and also by metabolic activity measurements. In particul... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974684 Sun, 26 Jun 2011 23:00:00 +0100 4974684 http://www.medworm.com/index.php?rid=4974683&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.435 AbstractCell‐based tissue engineering strategies have shown tremendous promise for the repair of bone mass deficiencies, but the efficient and appropriate induction of stem cells down osteogenic pathways remains a significant roadblock to the effective implementation of cell‐based therapies. When grown in culture, human Mesenchymal Stromal/Stem Cells (hMSCs) remain multipotent, requiring specific exogenous signals to induce osteogenic differentiation. hMSCs used in transplantations, therefore, must be presented with local signals, often provided by the host's own tissues, to be directed down bone‐related lineages. This process is relatively inefficient and remains difficult to control. In an effort to enhance osteogenesis, hMSCs were transfected with specific miRNA mimics and inhibit... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4974683 Sun, 26 Jun 2011 23:00:00 +0100 4974683 http://www.medworm.com/index.php?rid=4932319&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.433 The objective of the study was to evaluate the fate and effect of allogenic bone marrow MSCs after transplantation into an IDD model. The L2–3, L3–4 and L4–5 intervertebral discs (IVDs) of four rabbits were stabbed to create IDD. Rabbit MSCs were expanded in vitro and in part transduced with retrovirus/eGFP. After 3 weeks, 1 × 105 MSCs were injected into the IVDs. The rabbits were followed by X‐ray and MRI 3 and 9 weeks after injection. Then the animals were sacrificed and the spines analysed histologically. MRI showed no signs of regeneration. X‐ray and gross anatomy inspection demonstrated large anterolateral osteophytes. Histological analysis showed that the osteophytes were composed of mineralized tissue surrounded by chondrocytes, with the labelled MSCs among the osteophyte... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4932319 Tue, 31 May 2011 23:00:00 +0100 4932319 http://www.medworm.com/index.php?rid=4852320&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.429 In this study, we tested the effects of all three TGFβ isoforms (‐β1, ‐β2 and ‐β3) on ECM production, as well as expression of fibrotic markers. HCFs were grown in four media conditions for 4 weeks: control, VitC only; T1, VitC + TGFβ1; T2, VitC + TGFβ2; and T3, VitC + TGFβ3. The cultures were analysed with western blots, TEM and indirect immunofluorescence (IF). Compared to controls, all TGFβ isoforms stimulated matrix production by about three‐fold. IF showed the presence of type III collagen and smooth muscle actin (SMA) in T1 and T2; however, T3 showed little to no expression. In western blots, T3 stimulated a lower type III:type I collagen ratio when compared to the other conditions. In addition, TEM indicated that T3 stimulated a higher level of matrix alignment and o... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4852320 Mon, 23 May 2011 16:07:14 +0100 4852320 http://www.medworm.com/index.php?rid=4788159&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.424 AbstractTendon/ligament injuries are very common in sports and other rigorous activities. Tendons regenerate and repair slowly and inefficiently in vivo after injury. The limited ability of tendon to self‐repair and the general inefficiencies of current treatment regimes have hastened the motivation to develop tissue‐engineering strategies for tissue repair. Of particular interest in recent years has been the use of adult mesenchymal stem cells (MSCs) to regenerate functional tendons and ligaments. Different sources of MSCs have been studied for their effects on tendon repair. However, ectopic bone and tumour formation has been reported in some special circumstances after transplantation of MSCs. The induction of MSCs to differentiate into tendon‐forming cells in vitro prior to trans... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4788159 Wed, 04 May 2011 23:00:00 +0100 4788159 http://www.medworm.com/index.php?rid=4788158&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.425 In this study, we aimed to deliver the TGF‐β3 gene into dedifferentiated chondrocytes with recombinant lentiviral vectors; by transgenic expression of TGF‐β3, chondrocytic redifferentiation is catalysed. Simultaneously, shRNA targeting Col I was also incorporated into the vector to suppress Col I production. The results indicated that chondrocytes underwent dedifferentiation in monolayer culture in the presence or absence of transgenic TGF‐β3. In three‐dimensional culture, effective redifferentiation was managed in the dedifferentiated chondrocytes that were transduced with transgenic TGF‐β3. The incorporation and expression of Col I‐targeting shRNA were also effective in reducing Col I production in a post‐transcriptional manner. Copyright © 2011 John Wiley & Sons, ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4788158 Wed, 04 May 2011 23:00:00 +0100 4788158 http://www.medworm.com/index.php?rid=4788157&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.426 AbstractThe extent of the influence of mesenchymal tissue on epithelial development is still debated, and elucidation of epithelial–mesenchymal interactions should be of relevance for controlling normal as well as pathological growth and development. The aim of the present study was to elucidate the influence of the mesenchymal cell type on oral mucosa epithelial development in vitro, using tissue‐engineering principles, by including three different sources for mesenchymal cell type, viz. oral mucosa, skin and cornea, each of them presenting a distinct type of epithelium in situ. We investigated epithelial–mesenchymal interactions, considering both morphological criteria and protein expression (filaggrin, keratin 10, keratin 12, keratin 13 and laminin 5). The results of the histology... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4788157 Wed, 04 May 2011 23:00:00 +0100 4788157 http://www.medworm.com/index.php?rid=4788156&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.427 AbstractBone marrow mesenchymal stem cells (MSCs) have been used for bone tissue engineering due to their osteogenic differentiation capability, but their application is controversial. To enhance their capability, we prepared biodegradable gelatin sponges incorporating β‐tricalcium phosphate ceramics (GT sponge), which has been shown to possess excellent controlled drug‐release properties. The GT sponge was used as a carrier for both rat MSCs and bone morphogenetic protein‐2 (BMP‐2) and osteogenic differentiation was assessed by subcutaneous implantation of four different kinds of implants, i.e. GT‐alone, MSC–GT composites, BMP–GT composites and BMP–GT composites supplemented with MSCs (BMP–MSC–GT) in rats. Two weeks after implantation, histological sections showed new... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4788156 Wed, 04 May 2011 23:00:00 +0100 4788156 http://www.medworm.com/index.php?rid=4788155&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.430 AbstractCartilage is a specialized tissue represented by a group of particular cells (the chondrocytes) and an abundant extracellular matrix. Because of the reduced regenerative capacity of this tissue, cartilage injuries are often difficult to handle. Nowadays tissue engineering has emerged as a very promising discipline, and biodegradable polymeric scaffolds are widely used as tissue supports. In cartilage injuries, the use of autologous chondrocyte implantation from non‐affected cartilage zones has emerged as a very interesting technique, where chondrocytes are expanded in order to obtain a greater number of cells. Nevertheless, it has been reported that chondrocytes in bidimensional cultures suffer a dedifferentiation process. The present study sought, in the first place, to standard... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4788155 Sat, 30 Apr 2011 23:00:00 +0100 4788155 http://www.medworm.com/index.php?rid=4703594&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.421 AbstractThe manufacturing technique for cotton‐candy floss, heat‐aided rotary jet‐spinning, was used to produce submicron‐scale fibrous meshes by using bioabsorbable thermoplastic polymers. The method was feasible for 100 wt% polymer concentrations functioning completely without solvents. It was possible to produce submicron diameter fibres using a simple device, which indicates that this manufacturing method is a very promising technique for obtaining high‐throughput rates for submicron, and possibly nano‐scale, fibrous meshes. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4703594 Thu, 31 Mar 2011 23:00:00 +0100 4703594 http://www.medworm.com/index.php?rid=4657914&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.423 AbstractThe purpose of this study was to investigate an engineered composite of multilayer acellular tendon slices seeded with bone marrow stromal cells (BMSCs) as a possible solution for tendon reconstruction. BMSCs were harvested from 15 rabbits and infraspinatus tendons were harvested from 17 dogs. The decellularized tendons were sectioned in longitudinal slices with a thickness of 50 µm. The BMSCs were seeded on the slices and then the slices were bundled into one composite. The composite was implanted into a rabbit patellar tendon defect. Tendon slices without BMSCs were implanted into the contralateral patellar tendon as a control. The composites were evaluated by histology and qRT–PCR. The viability of BMSCs was assessed using a fluorescent marker. Histology showed viable cells b... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4657914 Thu, 31 Mar 2011 04:06:23 +0100 4657914 http://www.medworm.com/index.php?rid=4652009&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.422 AbstractA common subject in bone tissue engineering is the need for porous scaffolds to support cell and tissue interactions aiming at repairing bone tissue. As poly(lactide‐co‐glycolide)–calcium phosphate (PLGA–CaP) scaffolds can be manufactured with different pore sizes, the aim of this study was to evaluate the effect of pore diameter on osteoblastic cell responses and bone tissue formation. Scaffolds were prepared with 85% porosity, with pore diameters in the ranges 470–590, 590–850 and 850–1200 µm. Rat bone marrow stem cells differentiated into osteoblasts were cultured on the scaffolds for up to 10 days to evaluate cell growth, alkaline phosphatase (ALP) activity and the gene expression of the osteoblast markers RUNX2, OSX, COL, MSX2, ALP, OC and BSP by real‐time PCR... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4652009 Wed, 30 Mar 2011 03:27:40 +0100 4652009 http://www.medworm.com/index.php?rid=4641707&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.419 In conclusion, a novel mannitol‐containing porous CPC–hUCMSC construct was developed for bone tissue engineering. Its advantages include cell delivery inside a load‐bearing CPC that has injectable and in situ setting capabilities. hUCMSCs inside CPC had good viability and successfully osteodifferentiated. The self‐setting and strong hUCMSC‐encapsulating CPC scaffold is promising for bone tissue engineering in a wide range of orthopaedic and craniofacial applications. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4641707 Mon, 28 Mar 2011 16:57:02 +0100 4641707 http://www.medworm.com/index.php?rid=4652010&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.420 AbstractApligraf®, a skin substitute currently used in skin chronic wound treatment, acts as a source of macromolecules and cytokines to promote wound healing. Normal collagen hydrogel (NCH), obtained from collagen at low concentration (0.66 mg/ml), is the base of the dermal layer. Apligraf has several drawbacks, such as poor persistence of fibroblasts within the normal collagen hydrogel. In the present study we have evaluated concentrated collagen hydrogels at 5 mg/ml (CCH5s) as dermal substitutes for the treatment of skin chronic wounds. The effect of raised collagen concentration on hydrogel stability, cell growth, apoptosis and fibroblast phenotype was evaluated over 21 days in culture. In contrast to NCHs, CCH5s were more stable because no contraction was observed during the first we... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4652010 Sun, 27 Mar 2011 23:00:00 +0100 4652010 http://www.medworm.com/index.php?rid=4641708&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.418 In this study we carried out a systematic and detailed physiological characterization of human liver cells in a 3D hollow‐fiber bioreactor system continuously run for > 2 weeks. Primary human hepatocytes were maintained viable and functional over the whole period of cultivation. Both general cellular functions, e.g. oxygen uptake, amino acid metabolism and substrate consumption, and liver‐specific functions, such as drug‐metabolizing capacities and the production of liver‐specific metabolites were found to be stable for > 2 weeks. As expected, donor‐to‐donor variability was observed in liver‐specific functions, namely urea and albumin production. Moreover, we show the maintenance of primary human hepatocytes in serum‐free conditions in this set‐up. The stable basal ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4641708 Sun, 27 Mar 2011 00:00:00 +0100 4641708 http://www.medworm.com/index.php?rid=4544426&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.407 AbstractThis paper describes a clinical case study in which a chitosan/polyglycolic acid nerve guidance conduit (chitosan–PGA NGC) was utilized to repair a 30 mm long median nerve defect in the right distal forearm of a 55 year‐old male patient. Thirty‐six months after the nerve repair, the palm abduction of the thumb and the thumb–index digital opposition recovered, facilitating the patient to accomplish fine activities, such as handling chopsticks. Static two‐point discrimination measured 14, 9 and 9 mm in the thumb, index and middle fingers of the right hand. Reproducible compound muscle action potentials were recorded on the right abductor pollicis. The ninhydrin test, a classical method for assessing sympathetic nerve function, showed partial recovery of the perspiration fun... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4544426 Thu, 03 Mar 2011 00:00:00 +0100 4544426 http://www.medworm.com/index.php?rid=4580622&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.413 This study sought to establish a chronic total occlusion (CTO) model with cell‐mediated calcium deposits in rabbit femoral arteries. CTO is the most severe case in atherosclerosis and contains calcium deposits. Previous animal models of CTO do not mimic the gradual occlusion of arteries or have calcium in physiological form. In the present study we tested the strategy of placing tissue‐engineering scaffolds preloaded with cells in arteries to develop a novel CTO model. Primary human osteoblasts (HOBs) were first cultured in vitro on polycaprolactone (PCL) scaffolds with 5 ng TGFβ1 loading for 28 days for precalcification. The HOB–PCL construct was then implanted into a rabbit femoral artery for an additional 3, 10 or 28 days. At the time of sacrifice, angiograms and gross histology ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4580622 Tue, 01 Mar 2011 00:00:00 +0100 4580622 http://www.medworm.com/index.php?rid=4574682&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.393 AbstractBone marrow mesenchymal stem cells (MSCs) are promising candidates for cell therapy and tissue engineering. We used mesenchymal stem cells from human bone marrow (hMSCs) as the seeding cells to investigate the potential of hepatocytic differentiation of hMSCs in porous polylactic glycolic acid (PLGA) scaffolds under perfusion induction. hMSCs were seeded and proliferated in PLGA scaffolds, and then induced into hepatocyte‐like cells with hepatogenic medium in perfusion and static cultures. The results showed that hMSCs could be induced into hepatocyte‐like cells in PLGA scaffolds with hepatogenic medium in both static and perfusion induction systems. However, perfusion induction was more effective for cellularity in PLGA scaffolds than in static induction. Cells in the scaffold... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4574682 Tue, 01 Mar 2011 00:00:00 +0100 4574682 http://www.medworm.com/index.php?rid=4570051&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.415 AbstractThe present work describes the feasibility of a cross‐linkable injectable hyaluronan hydrogel for cartilage repair. The hydrogel used is a two‐component system based on aldehyde‐modified hyaluronan and hydrazide‐modified polyvinyl alcohol, which are rapidly cross‐linked in situ upon mixing. The in vitro study showed that chondrocytes and mesenchymal cells cultured in the gel form cartilage‐like tissue, rich in glycosaminoglycans, collagen type II and aggrecan. In a rabbit animal model the injection of the hydrogel improved the healing of a full‐thickness cartilage defect created in the knee as compared to non‐treated controls. This rabbit study showed that the regenerated cartilage defects stained more intensely for type II collagen upon treatment with the hydrogel.... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4570051 Tue, 01 Mar 2011 00:00:00 +0100 4570051 http://www.medworm.com/index.php?rid=4544425&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.417 The objective of this study was to determine the expression patterns of myogenic markers within the human satellite cell population during their differentiation into multinucleated myotubes for an accurate characterization of stem cell behaviour. Satellite cells were incubated (for 1, 4, 8, 12 or 16 days) with a culture medium containing either a low [ = differentiation medium (DM)] or high [ = growth medium (GM)] concentration of growth factors. Furthermore, we performed a quantitative gene expression analysis of well‐defined differentiation makers: myogenic factor 5 (MYF5), myogenin (MYOG), skeletal muscle αactin1 (ACTA1), embryonic (MYH3), perinatal (MYH8) and adult skeletal muscle myosin heavy chain (MYH1). Additionally, the fusion indices of forming myotubes of MYH1, MYH8 and ACTA1... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4544425 Tue, 01 Mar 2011 00:00:00 +0100 4544425 http://www.medworm.com/index.php?rid=4531439&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.416 The objective of this study was to evaluate whether growth factors (FGF‐2, FGF‐4 and FGF‐6) used alone or in combination with TGFβ2 are able to increase the proliferation and induce the differentiation of human bone marrow mesenchymal stem cells (hMSCs) to chondrocytes, with a view to using them in cartilage tissue engineering. Cells cultured in monolayer, used to test the activity of the growth factors on cell proliferation, showed that a combination of FGFs with TGFβ2 increases cell proliferation compared to cells cultured in control medium or in the presence of growth factors alone. The chondrogenic potential, evaluated in three‐dimensional (3D) cell aggregates, showed that FGF‐2 and FGF‐6, when used in combination with TGFβ2 increased the size and glycosaminoglycan conte... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4531439 Tue, 01 Mar 2011 00:00:00 +0100 4531439 http://www.medworm.com/index.php?rid=4521524&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.412 AbstractTissue engineering strategies for the intervertebral disc (IVD) have traditionally focused either on the annulus fibrosus (AF) or the nucleus pulposus (NP) in isolation, or have simply compared AF cells and NP cells in identical culture conditions. Recently, others in the field have become aware of the advantage of combining the AF and NP into a more comprehensive strategy to address IVD tissue engineering, and have introduced biomimetic approaches to either AF or NP tissue engineering. Here, we introduced a new method for developing a biomimetic, cell‐seeded IVD by electrospinning circumferentially‐orientated polycaprolactone fibres (AF analogue), seeding them with cells (porcine chondrocytes) and then gelling a cell–agarose solution in the centre (NP analogue). Scanning ele... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4521524 Sat, 26 Feb 2011 00:35:19 +0100 4521524 http://www.medworm.com/index.php?rid=4516698&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.414 AbstractClinical translation of engineered tissues into regenerative medicine applications, and the effort to reduce the use of animals for the screening of drugs and other compounds, result in an increasing demand for human tissues engineered in vitro for implantation, in vitro screening systems and basic research. Further development and optimization of in vitro models for quantitative studies of biophysical stimulation and mass transport in engineered tissues is seen as one of the high research priorities. A recent international symposium held in The Netherlands discussed the state of the art and key challenges in the development of bioreactor platforms and microscale technologies. Here we summarize the current status and future development of in vitro tissue models, based on the findin... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516698 Fri, 25 Feb 2011 00:41:37 +0100 4516698 http://www.medworm.com/index.php?rid=4516704&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.405 In conclusion, these results, although preliminary, provide clues for the design of new therapeutic strategies for skin regeneration, consisting in the combination of mesenchymal stem cells with engineered biomaterials. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516704 Thu, 24 Feb 2011 00:00:00 +0100 4516704 http://www.medworm.com/index.php?rid=4516703&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.406 AbstractComposite scaffolds prepared from natural polymers and hydroxyapatite (HA) are expected to have enhanced osteoconductive properties and as a result gained much attention in recent years for use in bone tissue‐engineering applications. Although there are various natural polymers available for this purpose, chitosan (C) and gelatin (G) are commonly studied because of their inherent properties. The aim of this study was to prepare three‐dimensional (3D) scaffolds using these two natural polymers and to add either non‐sintered hydroxyapatite (nsHA) or sintered hydroxyapatite (sHA) to compare their influence on physical, chemical and mechanical properties of the scaffolds and on their affinities towards Saos‐2 cells. For this purpose, nsHA and sHA were synthesized and characteri... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516703 Thu, 24 Feb 2011 00:00:00 +0100 4516703 http://www.medworm.com/index.php?rid=4516702&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.408 In conclusion, this study suggests that MMPs have complex interactions in both pathobiology and homeostasis. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516702 Thu, 24 Feb 2011 00:00:00 +0100 4516702 http://www.medworm.com/index.php?rid=4516701&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.409 AbstractThe recent introduction of stem cells in cardiology provides new tools in understanding the regenerative processes of the normal and pathological heart and has opened a search for new therapeutic strategies. Recent published reports have contributed to identifying possible cellular therapy approaches to generate new myocardium, involving transcoronary and intramyocardial injection of progenitor cells. However, one of the limiting factors in the overall interpretation of clinical results obtained by cell therapy is represented by the lack of three‐dimensional (3D) high‐resolution methods for the visualization of the injected cells and their fate within the myocardium. This work shows that X‐ray computed microtomography may offer the unique possibility of detecting, with high d... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516701 Thu, 24 Feb 2011 00:00:00 +0100 4516701 http://www.medworm.com/index.php?rid=4516700&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.410 In conclusion, our study indicated no difference in the rate of vascularization of prevascularized ASC/HUVEC and non‐prevascularized ASC‐only fibrin‐based constructs, suggesting that prevascularization of these fibrin‐based constructs does not promote vascularization. Our results further indicated that not only endothelial cells, but also ASCs may contribute to the formation of vascular lumina upon implantation. This finding is interesting, since it demonstrates the possibility of vascularized adipose tissue engineering from a single cell source. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516700 Thu, 24 Feb 2011 00:00:00 +0100 4516700 http://www.medworm.com/index.php?rid=4516699&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.411 AbstractThe delivery of growth factors to aid in cartilage engineering has received considerable attention. However, phenotypical differences between chondrocyte cell populations and their distinct responses to growth factors are not fully understood. To address this issue, we have investigated the gene expression of chondrocytes isolated from the superficial, middle, and deep zones of bovine articular cartilage. A three‐dimensional (3D) alginate bead model was used to encapsulate zonal chondrocytes and culture with or without exogenous insulin‐like growth factor‐1(IFG‐1) delivery. Following culture, mRNA expression of type I collagen, type II collagen, aggregan, IGF‐1 and IGF‐1 binding protein (IGF‐BP3) were analysed at 1, 4 and 8 days. To the best of our knowledge, this is ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4516699 Thu, 24 Feb 2011 00:00:00 +0100 4516699 http://www.medworm.com/index.php?rid=4501114&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.404 AbstractPorcine skin‐derived mesenchymal stem cells (pSMSCs) were evaluated on their biological MSC characterizations and differentiation into mesenchymal lineages, along with in vitro and in vivo neural inductions. Isolated pSMSCs showed plate‐adherent growth, expression of various MSC‐marker proteins and transcriptional factors, and differentiation potential into mesenchymal lineages. Neuron‐like cell morphology and various neural markers were highly detected at 6 h and 24 h after in vitro neural induction of pSMSCs, but their neuron‐like characteristics disappeared as induction time extended to 48 and 72 h. To evaluate the in vivo peripheral nerve regeneration potential of pSMSCs, a total of 5 × 106 autologous pSMSCs labelled with tracking dye, supplemented with fibrin glue s... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4501114 Mon, 21 Feb 2011 16:27:13 +0100 4501114 http://www.medworm.com/index.php?rid=4501115&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.403 AbstractMesenchymal stromal cells are present in very low numbers in the bone marrow, necessitating their selective expansion on tissue culture plastic prior to their use in tissue‐engineering applications. MSC expansion is laborious, time consuming, unphysiological and not economical, thus calling for automated bioreactor‐based strategies. We and others have shown that osteogenic grafts can be cultured in bioreactors by seeding either 2D‐expanded cells or by direct seeding of the mononuclear fraction of bone marrow. To further streamline this protocol, we assessed in this study the possibility of seeding the cells onto porous calcium phosphate ceramics directly from unprocessed bone marrow. Using predetermined volumes of bone marrow from multiple human donors with different nucleate... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4501115 Mon, 21 Feb 2011 00:00:00 +0100 4501115 http://www.medworm.com/index.php?rid=4464063&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.390 AbstractAlthough hydroxyapatite (HAP) and β‐tricalcium phosphate have been used extensively as osteoconductive minerals in biomaterial scaffolds for bone regeneration, they lack the capacity to stimulate osteoblastic differentiation of progenitor cells. In contrast, amorphous calcium phosphates (ACPs), which convert to HAP under aqueous conditions, have the potential to facilitate osteoblastic differentiation through the transient local release of calcium and phosphate ions. Therefore, in this study ACPs were synthesized using zinc and zirconia divalent cations as stabilizers (denoted ZnACP and ZrACP, respectively) and compared to HAP. Analysis of ion release into serum‐containing cell culture medium revealed transiently elevated levels of calcium and phosphorous, consistent with the ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464063 Thu, 10 Feb 2011 00:00:00 +0100 4464063 http://www.medworm.com/index.php?rid=4464062&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.391 In this study, chitosan‐based scaffolds were seeded and cultured in vitro with hBMSCs for 3 weeks under osteogenic stimulation conditions and analysed for cell adhesion, proliferation and differentiation. Implantation of 2 weeks precultured cell constructs in osteogenic culture conditions was performed into critical cranial size defects in nude mice. The objective of this study was to verify the scaffold integration and new bone formation. At 8 weeks of implantation, scaffolds were harvested and prepared for micro‐computed tomography (µCT) analysis. Retrieved implants showed good integration with the surrounding tissue and significant bone formation, more evident for the scaffolds cultured and implanted with human cells. The results of this work demonstrated that chitosan‐based scaf... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464062 Thu, 10 Feb 2011 00:00:00 +0100 4464062 http://www.medworm.com/index.php?rid=4464061&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.392 AbstractReviewing the available literature, one could conclude that marrow‐derived mesenchymal stem cells (BMSCs) are the ‘gold standard’ source for bone tissue engineering applications, due to their multilineage differentiation potential and easy accessibility. However, comprehensive studies comparing their osteogenic potential with bone‐derived osteoblasts (OBs) to justify the preferred application of BMSCs based on performance are few. To address these shortfalls, in the present study, ovine BMSCs and OBs seeded onto scaffolds were characterized in vitro and transplanted subcutaneously into NOD/SCID mice in combination with and without recombinant human bone morphogenetic protein 7 (rhBMP‐7). It was hypothesized that cell origin, ossification type and degree of vascularization... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464061 Thu, 10 Feb 2011 00:00:00 +0100 4464061 http://www.medworm.com/index.php?rid=4464060&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.394 In conclusion, a novel biocompatible HAP–Blend composite with uniform dispersion of semi‐nano HAP particles and good interphase compatibility has been prepared successfully. The development of HAP–Blend composite, with improved physical, mechanical and osteoinductive properties, may potentially be used in bone tissue‐engineering applications. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464060 Thu, 10 Feb 2011 00:00:00 +0100 4464060 http://www.medworm.com/index.php?rid=4464059&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.395 In this study we investigated the roles of the cAMP‐dependent protein kinase A (PKA) signalling in proliferation, differentiation and mineralization of osteoblast‐like MC3T3‐E1 cells, using the PKA‐specific small molecule cAMP analogue, 6‐Bnz‐cAMP, at 100 µM. Alkaline phosphatase (ALP) activity, runt transcription factor 2 (Runx2), osteopontin (OPN) and osteocalcin (OCN) protein expressions were used as osteoblast‐specific markers to demonstrate osteoblastic differentiation. Further, calcium measurement of the extracellular matrix was employed as the hallmark of matrix mineralization or calcification. We report here that activation of PKA by the small molecule 6‐Bnz‐cAMP induces osteoblastic differentiation and matrix mineralization of osteoblast‐like MC3T3‐E1 cells.... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464059 Thu, 10 Feb 2011 00:00:00 +0100 4464059 http://www.medworm.com/index.php?rid=4454669&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.396 In this study a phase‐separation technique was used to produce a porous 3D HCG scaffold, containing a network of cross‐linked chitosan and gelatin fibrils coated in hydroxyapatite, with pore size readily controlled by freezing temperature. The HCG scaffolds were then seeded with human mesenchymal stem cells (hMSCs), using a depth filtration system after preconditioning with serum‐containing medium for 7 days under either static or perfusion conditions. The effects of static and perfusion media preconditioning on protein adsorption, surface morphology, hMSC attachment, proliferation and osteogenic differentiation were examined. Perfusion preconditioning, as opposed to static preconditioning, enhances adsorption of ECM proteins, which in turn promotes hMSC proliferation and osteogenic ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4454669 Tue, 08 Feb 2011 00:00:00 +0100 4454669 http://www.medworm.com/index.php?rid=4454668&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.397 In this study, we developed a method to construct flat fibrillar type I collagen scaffolds, 6 cm in diameter and with a radially orientated pore structure, by the use of directional freezing. Different methodologies were tested, the optimal one being freezing of a collagen suspension inside‐out, using a centrally positioned liquid nitrogen‐cooled tube. Pore sizes could be varied by the use of different tube materials. Use of aluminium tubes resulted in radial scaffolds with a pore size of 20–30 µm, whereas use of stainless steel produced radial scaffolds with 70–100 µm pore sizes. Brass‐ and copper‐based tubes produced scaffolds with less homogeneous radial pores, pore sizes being 90–100 and 50–80 µm, respectively. Fibreglass tubes gave even less uniformity (pore size 10... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4454668 Tue, 08 Feb 2011 00:00:00 +0100 4454668 http://www.medworm.com/index.php?rid=4454667&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.398 In this study, we have shown the effect of the mechanical stress on elastin synthesis, which has a direct effect on the mechanical properties of the tissue‐engineered vessel. We measured and compared the stress–strain curves, the elastic modulus and tenacity of a collagen tubular scaffold in the presence of C2C12 murine myoblasts cells, before and after the maturation in the bioreactor, applying a shear stress of 5 dynes/cm2 for 3 days. Interesting evidence concerning the extracellular matrix structure, which significantly modify the biomechanical characteristics of the cellular scaffold, were observed, underlying the importance of focusing more effort in the research field of physiologically‐guided 3D tissue‐engineered substitutes. Copyright © 2011 John Wiley & Sons, Ltd. (So... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4454667 Tue, 08 Feb 2011 00:00:00 +0100 4454667 http://www.medworm.com/index.php?rid=4454666&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.399 In conclusion, this study suggests that TGFβ subtypes do affect terminal differentiation of in vitro cultured hBMSCs differently. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4454666 Tue, 08 Feb 2011 00:00:00 +0100 4454666 http://www.medworm.com/index.php?rid=4477008&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.401 AbstractAllogenic bone grafting, a technique used in orthopaedic surgery, has several problems, including low osteogenic activity. To overcome the problem, this study aimed to determine whether in vivo osteogenesis could be enhanced using allogenic irradiated bone grafts after seeding with autologous bone marrow‐derived mesenchymal stem cells (BMSCs). The allogenic bone cylinders were extracted from ACI rats and sterilized by irradiation. Donor BMSCs were obtained from fresh Fischer 344 (F344) rat bone marrow by cell culture. The allogenic bone with or without BMSCs were transplanted subcutaneously into syngeneic F344 rats. At 4 weeks after transplantation, high alkaline phosphatase (ALP) activity, bone‐specific osteocalcin mRNA expression and newly formed bone were detected in the all... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4477008 Tue, 01 Feb 2011 00:00:00 +0100 4477008 http://www.medworm.com/index.php?rid=4464058&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.402 AbstractFor the success of any biomaterial for tissue engineering, its mechanical properties and ability to support nutrient diffusion will be critical. Collagen scaffolds are ideal candidates, due to their ability to immerse cells in a biomimetic nanofibrous matrix. We have established O2 diffusion coefficients through native, dense collagen scaffolds at two tissue‐like densities, with and without photo‐chemical crosslinking, by adapting an optical fibre‐based system for real‐time core O2 monitoring deep within collagen constructs. Using a Fick's law model, we then derived O2 diffusion coefficients; 4.5 × 10−6 cm2/s for 11% density collagen scaffolds; 1.7 × 10−6 cm2/s for 34% collagen scaffolds; 3.4 × 10−6 cm2/s for photochemically crosslinked collagen scaffolds at 11%. B... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4464058 Tue, 01 Feb 2011 00:00:00 +0100 4464058 http://www.medworm.com/index.php?rid=4454665&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.400 This study aimed to identify an efficient, minimally invasive and economical DPC transplantation procedure for use in clinical settings. Five clinically applicable transplantation procedures were tested, termed the Pinhole, Laser, Slit, Non‐vascularized sandwich (NVS) and Hemi‐vascularized sandwich (HVS) methods. Labelled rat dermal papilla tissue was transplanted into rat sole skin, and hair follicle regeneration was evaluated histologically. Regenerated follicles and labelled DPCs were detected for all methods, although some follicles showed abnormal growth, i.e. a cystic or inverted appearance. The HVS method, pioneered here, resulted in significantly larger number of regenerated follicles that were more mature and regular than those observed using the other methods. Moreover, hair ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4454665 Tue, 01 Feb 2011 00:00:00 +0100 4454665 http://www.medworm.com/index.php?rid=4436382&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.388 AbstractThe first stem cells considered for the reconstruction of bone were bone marrow mesenchymal stem cells (BMSCs). Subsequently, cells with similar marker expression panel and differentiation potential were found in new sources of cells, such as adipose tissue. This source of stem cells has a promising future in tissue‐engineering applications, considering the abundance of this tissue in the human body, the easy harvesting and the high number of stem cells that are available from such a small amount of tissue. The isolation of the adipose stem cells is generally performed by means of enzymatic digestion of the tissues, followed by a natural selection of the stem cells based on their capacity to adhere to the culture flasks, leading to a quite heterogeneous population. This constitut... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4436382 Tue, 01 Feb 2011 00:00:00 +0100 4436382 http://www.medworm.com/index.php?rid=4398880&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.365 AbstractTransplantation of bone marrow mesenchymal stem cells (BM‐MSCs) has been shown to ameliorate the injured central nervous system (CNS). Although these effects were initially attributed to the putative differentiation of MSCs towards the neural lineage, it is now known that most of them are mediated by the secretome. Up to now most in vitro reports have dealt with the effects of the secretome on neural stem cells and their differentiation. Consequently, there is a lack of information regarding the role of the secretome on the viability and survival of pre‐existent matured differentiated cell populations. Moreover, it is also not known how the time points of conditioned media (CM) collection affect such parameters. In the present study, primary cultures of hippocampal neurons and ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4398880 Wed, 26 Jan 2011 16:27:51 +0100 4398880 http://www.medworm.com/index.php?rid=4398881&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.364 AbstractBone marrow has been the elected cell source of studies published so far concerning bone and cartilage tissue‐engineering approaches. Recent studies indicate that adipose tissue presents significant advantages over bone marrow as a cell source for tissue engineering. Most of these studies report the use of adipose stem cells (ASCs) isolated by a method based on the enzymatic digestion of the adipose tissue and on the ability of stem cells to adhere to a cell culture plastic surface. Using this method, a heterogeneous population was obtained containing different cell types that have been shown to compromise the proliferation and differentiation potential of the stem cells. This paper reports the development and optimization of a new isolation method that enables purified cell popu... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4398881 Wed, 26 Jan 2011 00:00:00 +0100 4398881 http://www.medworm.com/index.php?rid=4360284&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.384 In conclusion, the US stimulation regimen employed was shown to modulate the proliferative capacity, biosynthetic activity and integrin mRNA expression of articular chondrocytes maintained in 3D matrices. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4360284 Mon, 17 Jan 2011 00:00:00 +0100 4360284 http://www.medworm.com/index.php?rid=4349035&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.358 In conclusion, COMP synthesis is differentially regulated by TGFβ1 in the surface and middle zones of bovine articular cartilage. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Journal of Tissue Engineering and Regenerative Medicine) Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4349035 Fri, 14 Jan 2011 00:00:00 +0100 4349035 http://www.medworm.com/index.php?rid=4330286&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.344 In this study, we altered expression of MHCI through viral immunomodulatory mechanisms to examine whether allogeneic cells could be made to ‘mimic’ viral evasion of a host CTL response. We demonstrate the successful application of a retroviral vector in vitro to overexpress the Kaposi's sarcoma‐associated herpesvirus immunomodulatory protein, MIR2, in human monocyte‐like myeloid progenitor cells. This approach led to differential downregulation of cell surface MHCI, ICAM‐1 and B7–2 molecules. We also demonstrate that downregulation of immunoactive molecules has the functional effect of significantly reducing T cell‐mediated cytotoxicity without altering NK‐mediated cytotoxicity in vitro. These results provide proof‐of‐concept that viral immune evasion strategies allow c... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4330286 Mon, 10 Jan 2011 00:00:00 +0100 4330286 http://www.medworm.com/index.php?rid=4330285&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.347 AbstractTo test the mechanical properties of regenerate cortical bone created using mandibular bone transport (MBT) distraction, five adult male American foxhound dogs underwent unilateral distraction of the mandible with a novel MBT device placed to linearly repair a 30–35 mm bone defect. The animals were sacrificed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical specimens were taken from the inner (lingual) and outer (buccal) plates of the reconstructed mandible and 21 control specimens were removed from the contralateral aspect of the mandible. The mechanical properties of the 35 cylindrical cortical bone specimens were assessed by using a non‐destructive pulse ultrasound technique. Results showed that all of the cortical mechanical properties exhibit ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4330285 Mon, 10 Jan 2011 00:00:00 +0100 4330285 http://www.medworm.com/index.php?rid=4330284&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.366 We reported previously that the implantation of capillary networks engineered ex vivo by the use of cell‐printing technology could improve blood perfusion. Here, we developed a new substrate prepared by coating glass with polyethylene glycol (PEG) to create a non‐adhesive surface and subsequent photo‐lithography to finely tune the adhesive property for efficient cell transfer. We examined the cell‐transfer efficiency onto amniotic membrane and bone regenerative efficiency in murine calvarial bone defect. Cell transfer of KUSA‐A1 cells (murine osteoblasts) to amniotic membrane was performed for 1 h using the substrates. Cell transfer using the substrate facilitated cell engraftment onto the amniotic membrane compared to that by direct cell inoculation. KUSA‐A1 cells transferred ... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4330284 Mon, 10 Jan 2011 00:00:00 +0100 4330284 http://www.medworm.com/index.php?rid=4330283&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.377 AbstractIn vitro application of pulsatile electrical stimulation to neonatal rat cardiomyocytes cultured on polymer scaffolds has been shown to improve the functional assembly of cells into contractile engineered cardiac tissues. However, to date, the conditions of electrical stimulation have not been optimized. We have systematically varied the electrode material, amplitude and frequency of stimulation to determine the conditions that are optimal for cardiac tissue engineering. Carbon electrodes, exhibiting the highest charge‐injection capacity and producing cardiac tissues with the best structural and contractile properties, were thus used in tissue engineering studies. Engineered cardiac tissues stimulated at 3 V/cm amplitude and 3 Hz frequency had the highest tissue density, the high... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4330283 Mon, 10 Jan 2011 00:00:00 +0100 4330283 http://www.medworm.com/index.php?rid=4330282&cid=s_36724_67_f&fid=36724&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fterm.378 We report a double‐crosslinking strategy of biocompatible and biodegradable hydrogels derived from aminated and oxidized hyaluronic acid (HA) with genipin (GP), a compound naturally derived from the gardenia fruit. Fast gelation is attributed to the Schiff‐base reaction between amino and aldehyde groups of polysaccharide derivatives, and the subsequent crosslinking with GP results in ideal biodegradability and mechanical properties. The gelation time, morphology, equilibrium swelling, compressive modulus and degradation of double‐crosslinked hydrogels were examined. The double crosslinked hydrogels were examined in vivo via subcutaneous injection into a mouse model. Histological results indicated favourable biocompatility, as revealed by an absence of neutrophils and macrophages. The... Journal of Tissue Engineering and Regenerative Medicine journals http://www.medworm.com/rss/comments.php?id=4330282 Mon, 10 Jan 2011 00:00:00 +0100 4330282