Enhancement of Chondrogenesis by a Microcavitary Hydrogel Coculture System Synergizing With SDF-1α and TGF-Β3

A favorable microenvironment is of great significance for the repair of cartilage injury. In our previous study, a coculture system was devised, integrating genetically modified chondrocytes expressing transforming growth factor (TGF)-β3 with ATDC5 cells, which demonstrated an augmented chondrogenesis effect. In this study, a delivery platform for the controlled release of stromal cell-derived factor (SDF)-1α was constructed based on our microcavitary hydrogel system. Subsequently, it was combined with the coculture system to explore the release patterns of SDF-1α and TGF-β3 and investigate their synergistic impact on chondrogenesis. The findings indicated that both SDF-1α and TGF-β3 could be continuously and efficiently released from the delivery system throughout the culture period. Moreover, the combined application of SDF-1α and TGF-β3 was able to enhance cell proliferative activity, as demonstrated by the Cell Counting Kit-8 data. Synergistically, it led to superior chondrogenesis, as evidenced by real-time PCR, Western blot analysis, and immunohistochemistry staining assays. This study offers the insight that this delivery system, integrating the coculture system and microcavitary hydrogels, holds substantial potential for cell recruitment and cartilage repair, and may be applicable in regenerative medicine for diverse tissues.