Repair of\nCartilage Defects Using ATDC5 Cells Treated\nwith BBR Loaded in Chitosan Hydrogel

In this study, we explore the cartilage defect repair\nmechanism\nby phosphocreatine-grafted chitosan hydrogels loaded with berberine-treated\nATDC5 cells (CSMP@BBR@ATDC5). Under the optimal concentrations of\nLPS and BBR ideal conditions, ATDC5 cell toxicity and proliferation\nwere detected with AM/PI and EdU staining. Additionally, qPCR and\nWestern blot were employed to detect the expression of the SIRT1/BMP4\nsignaling pathway and chondrogenic-related factors in ATDC5 cells.\nMoreover, BBR-treated ATDC5 was seeded into a phosphocreatine-grafted\nchitosan hydrogel system. Subsequently, the cartilage defect was established\nin mice. After 4, 8, and 12 weeks, knee specimens were collected to\nevaluate the repair of cartilage defects. According to our findings,\nBBR can increase ATDC5 viability by LPS treatment. Likewise, it upregulates\nthe SIRT1/BMP4 signaling pathway expression and chondrogenic-related\nfactors. Another, it was shown by histological observation that the\ncartilage defect had been repaired more effectively in the CSMP@BBR@ATDC5\ngroup than in the other groups. Finally, the expressions of chondrogenic-related\nfactors and SIRT1/BMP4 signaling pathway were upregulates in CSMP@BBR@ATDC5\nthan in other groups. <i>In vitro,</i> BBR protects inflammatory\nATDC5 cells and maintains the expression of chondrogenic-related factors.\nSubsequently, we successfully use CSMP@BBR@ATDC 5 to repair knee cartilage\ndefects in mice.