Chondrogenesis of Synovium-Derived Mesenchymal Stem Cells in Photopolymerizing Hydrogel Scaffolds

Recently, tissues adjacent to the wound sites are regarded as a promising therapeutic cell source for curing and repairing purpose. Specifically, therapeutic stem cells have been identified in synovial tissue, a tissue adjacent to articular cartilage. The purpose of this study was to explore therapeutic chondrogenesis with rabbit synovium-derived mesenchymal stem cells (SMSCs) encapsulated in photopolymerized hydrogels. A non-degradable poly(ethylene glycol) diacrylate (PEGDA)-based hydrogel and biodegradable phosphoester-poly(ethylene glycol) (PhosPEG)-based hydrogel were both applied as 3-D scaffolds mediating SMSC chondrogenesis in vitro. The viability of SMSCs in both hydrogels was assessed by fluorescent Live/Dead assay and WST-1 assay. Levels of genes and proteins specific to SMSC chondrogenesis were evaluated by real-time RT-PCR, biochemical analysis and immunohistochemical analysis, respectively. The results demonstrated that SMSCs continue to have a high viability when encapsulated in the hydrogel. By treatment with transforming growth factor (TGF)-beta 1 or TGF-beta 3, positive SMSC chondrogenesis was successfully achieved in both gels, with the best outcome in the PEGDA system. It can be concluded that both PEGDA and PhosPEG hydrogels are appropriate cell-delivery vehicles for SMSC chondrogenesis. Especially as a biodegradable material, PhosPEG hydrogel displayed great potentials in future applications for articular cartilage regeneration coupling with SMSCs. (C) Koninklijke Brill NV, Leiden, 2010