title: Cartilage tissue engineering application of injectable gelatin hydrogel with in situ visible-light-activated gelation capability in both air and aqueous solution.
abstract: Chondroprogenitor cells encapsulated in a chondrogenically supportive, three-dimensional hydrogel scaffold represents a promising, regenerative approach to articular cartilage repair. In this study, we have developed an injectable, biodegradable methacrylated gelatin (mGL)-based hydrogel capable of rapid gelation via visible light (VL)-activated crosslinking in air or aqueous solution. The mild photocrosslinking conditions permitted the incorporation of cells during the gelation process. Encapsulated human-bone-marrow-derived mesenchymal stem cells (hBMSCs) showed high, long-term viability (up to 90 days) throughout the scaffold. To assess the applicability of the mGL hydrogel for cartilage tissue engineering, we have evaluated the efficacy of chondrogenesis of the encapsulated hBMSCs, using hBMSCs seeded in agarose as control. The ability of hBMSC-laden mGL constructs to integrate with host tissues after implantation was further investigated utilizing an in vitro cartilage repair model. The results showed that the mGL hydrogel, which could be photopolymerized in air and aqueous solution, supports hBMSC growth and TGF-β3-induced chondrogenesis. Compared with agarose, mGL constructs laden with hBMSCs are mechanically stronger with time, and integrate well with native cartilage tissue upon implantation based on push-out mechanical testing. VL-photocrosslinked mGL scaffold thus represents a promising scaffold for cell-based repair and resurfacing of articular cartilage defects.
authors.affiliation: 1 Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania.
authors.forename: Hang
authors.initials: H
authors.lastname: Lin
authors.forename: Anthony Wai-Ming
authors.initials: AW
authors.lastname: Cheng
authors.forename: Peter G
authors.initials: PG
authors.lastname: Alexander
authors.forename: Angela M
authors.initials: AM
authors.lastname: Beck
authors.forename: Rocky S
authors.initials: RS
authors.lastname: Tuan
mesh_terms: D020341:Absorbable Implants; D000388:Air; D002356:Cartilage / Q000166:cytology* / Q000254:growth & development*; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000502:physiology*; D019245:Compressive Strength / Q000502:physiology / Q000528:radiation effects; D005780:Gelatin / Q000008:administration & dosage / Q000737:chemistry* / Q000528:radiation effects; D006244:Hardness / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D020100:Hydrogels / Q000008:administration & dosage / Q000737:chemistry* / Q000528:radiation effects; D007267:Injections / Q000379:methods; D008027:Light; D008422:Materials Testing; D045164:Mesenchymal Stem Cell Transplantation / Q000295:instrumentation / Q000379:methods*; D012996:Solutions; D054457:Tissue Scaffolds; D014783:Viscosity / Q000528:radiation effects; D014867:Water / Q000737:chemistry
chemical_list: D020100:Hydrogels; D012996:Solutions; D014867:Water; D005780:Gelatin