title: Chondrogenic differentiation potential of human mesenchymal stem cells photoencapsulated within poly(ethylene glycol)-arginine-glycine-aspartic acid-serine thiol-methacrylate mixed-mode networks.
abstract: Chondrogenesis of human mesenchymal stem cells (hMSCs) encapsulated in poly(ethylene glycol) (PEG)-based hydrogels was studied in the presence and absence of 5 ng/mL transforming growth factor beta and chondrogenic medium to better understand the role of the gel environment on this process. The lack of any cell-polymer interactions led to decreasing cell viability, as measured using adenosine triphosphate, over a 14-day period. The extent of chondrogenic differentiation was evaluated by immunostaining, and although viability dramatically decreased, cells cultured in chondrogenic differentiation medium expressed higher levels of collagen type II. Cells cultured in hMSC control medium remained undifferentiated and continued to express CD105, a MSC marker. To increase cell survival, arginine-glycine-aspartic acid-serine (RGDS) was incorporated into gels using a novel mixed-mode thiol-ene reaction by synthesizing a cysteine-cysteine-arginine-glycine-aspartic acid-serine-cysteine-cysteine-glycine, N-terminus to C-terminus peptide sequence with pendant cysteine residues. A concentration of 5 mM RGDS incorporated into the network maintained 75% viability in control cultures. Further studies demonstrated that 5-mM RGDS chondrogenic cultures had greater gene expression for aggrecan and collagen II in conjunction with producing twice as much glycosaminoglycan as 0-mM chondrogenic cultures and 7 times that of control cultures. Incorporation of this peptide sequence not only allows for sustained viability, but also contributes to initiating chondrogenesis.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Chelsea N
authors.initials: CN
authors.lastname: Salinas
authors.forename: Brook B
authors.initials: BB
authors.lastname: Cole
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Kasko
authors.forename: Kristi S
authors.initials: KS
authors.lastname: Anseth
mesh_terms: D053674:Aggrecans / Q000096:biosynthesis; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects; D024043:Collagen Type II / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020100:Hydrogels; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D009842:Oligopeptides; D011092:Polyethylene Glycols; D011102:Polyhydroxyethyl Methacrylate; D013438:Sulfhydryl Compounds; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D053674:Aggrecans; D024043:Collagen Type II; D020100:Hydrogels; D009842:Oligopeptides; D013438:Sulfhydryl Compounds; D016212:Transforming Growth Factor beta; D011102:Polyhydroxyethyl Methacrylate; D011092:Polyethylene Glycols; C046617:arginyl-glycyl-aspartyl-serine