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Regenerative Medicine Applications (regenerative + medicine_application)
Selected AbstractsOptimization of the culturing conditions of human umbilical cord blood-derived endothelial colony-forming cells under xeno-free conditions applying a transcriptomic approachGENES TO CELLS, Issue 7 2010Steffen M. Zeisberger Establishment of fetal bovine serum (FBS)-free cell culture conditions is essential for transplantation therapies. Blood-derived endothelial colony-forming cells (ECFCs) are potential candidates for regenerative medicine applications. ECFCs were isolated from term umbilical cord blood units and characterized by flow cytometry, capillary formation and responsiveness to cytokines. ECFCs were expanded under standard, FBS-containing endothelial medium, or transferred to chemically defined endothelial media without FBS. Microarray expression profiling was applied to compare the transcriptome profiles in FBS-containing versus FBS-free culture. ECFC outgrowth in standard medium was successful in 92% of cord blood units. The karyotype of expanded ECFCs remained normal. Without FBS, ECFC initiation and expansion failed. Modest proliferation, changes in cell morphology and organization and cell death have been observed after passaging. Gene ontology analysis revealed a broad down-regulation of genes involved in cell cycle progression and up-regulation of genes involved in stress response and apoptosis. Interestingly, genes participating in lipid biosynthesis were markedly up-regulated. Detection of several endothelial cell-specific marker genes showed the maintenance of the endothelial cell characteristics during serum-free culture. Although ECFCs maintain their endothelial characteristics during serum-free culturing, they could not be expanded. Additional supply of FBS-free media with lipid concentrates might increase the ECFC survival. [source] Controlling Affinity Binding with Peptide-Functionalized Poly(ethylene glycol) HydrogelsADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Chien-Chi Lin Abstract Poly(ethylene glycol) (PEG) hydrogels functionalized with peptide moieties have been widely used in regenerative medicine applications. While many studies have suggested the importance of affinity binding within PEG hydrogels, the relationships between the structures of the peptide motifs and their binding to protein therapeutics remain largely unexplored, especially in the recently developed thiol-acrylate photopolymerization systems. Herein, Förster resonance energy transfer (FRET) and thiol-acrylate photopolymerizations are employed to investigate how the architectures of affinity peptides in crosslinked hydrogels affect their binding to diffusible proteins. The binding between diffusible streptavidin and biotinylated peptide immobilized to PEG hydrogel network was used as a model system to reveal the interplay between affinity binding and peptide sequences/architectures. In addition, peptides with different structures are designed to enhance affinity binding within PEG hydrogels and to provide tunable affinity-based controlled delivery of basic fibroblast growth factor (bFGF). This study demonstrates the importance of affinity binding in controlling the availability of hydrogel-encapsulated proteins and provides strategies for enhancing affinity binding of protein therapeutics to bound peptide moieties in thiol-acrylate photopolymerized PEG hydrogels. The results presented herein should be useful to the design and fabrication of hydrogels that retain and exhibit sustained release of growth factors for promoting tissue regeneration. [source] Myogenic Induction of Aligned Mesenchymal Stem Cell Sheets by Culture on Thermally Responsive Electrospun Nanofibers,ADVANCED MATERIALS, Issue 19 2007M. Dang A thermally reversible culture substrate with a topographically active surface of aligned nanofibers is able to induce cytoskeletal alignment and nucleus elongation. These morphological changes induce myogenic differentiation in stem cells. The differentiated cells can be recovered in sheet form by thermally induced dissolution of the substrate. A surface able to provide topographical cues to create an aligned stem cell sheet, activated to differentiate to a specific lineage, can have a significant impact on engineering of tissue constructs for regenerative medicine applications. [source] Induction of chondrogenesis from human embryonic stem cells without embryoid body formation by bone morphogenetic protein 7 and transforming growth factor ,1ARTHRITIS & RHEUMATISM, Issue 12 2009Toshiyuki Nakagawa Objective Human embryonic stem cells (ESCs) provide an unlimited supply of pluripotent cells for articular cartilage tissue engineering and regenerative medicine applications. Articular cartilage is an avascular tissue with precise polarity and organization comprising 3 distinct functional zones: surface, middle, and deep. To date, attempts at differentiating human ESCs into articular chondrocytes have been unsuccessful. The majority of studies have focused on chondrogenic (but not specifically articular cartilage) differentiation. Furthermore, previous investigations of induction of chondrogenesis by human ESCs required embryoid body formation; however, embryoid body formation often results in heterogeneous differentiation. The present study was undertaken to determine the in vitro chondrogenic potential of bone morphogenetic protein 7 (BMP-7) and transforming growth factor ,1 (TGF,1),induced human ESC differentiation toward the articular cartilage phenotype. Methods Dissociated single human ESCs were cultured and passaged on a gelatin-coated flask. The human ESCs were cultured as an aggregate in a pellet culture system for 14 days in basal chondrogenic medium (CM), CM with TGF,1, CM with BMP-7, or CM with both TGF,1 and BMP-7. Results The size and wet weight of the cartilage pellets and glycosaminoglycan levels increased, with the smallest, intermediate, and greatest increases, respectively, observed with CM plus TGF,1 treatment, CM plus BMP-7 treatment, and CM plus TGF,1 and BMP-7 treatment (compared with CM treatment alone). The largest size and highest weight of the pellet was in the group in which TGF,1 and BMP-7 were added to the medium. However, expression of the genes for cartilage-specific aggrecan and type II collagen II, as assessed by determination of messenger RNA levels, was highest in the BMP-7,treated group. Superficial zone protein (SZP)/lubricin, a marker of the superficial zone articular chondrocyte, was not detectable under identical culture conditions. Conclusion These results demonstrate an efficient and reproducible model system of human ESC-induced chondrogenesis, using a novel direct plating method in which intervening embryoid body formation does not occur. Further work is needed for optimization of conditions to obtain the articular cartilage phenotype that includes the superficial zone marker as demonstrated by SZP/lubricin synthesis. [source] | ||||||||||