Effects of different concentrations of BMSCs-Exos on the proliferation and differentiation of CSCPs and chondrocytes. (A, B) Immunofluorescence staining confirmed that CSCPs and chondrocytes phagocytosed BMSCs-Exos. (C, D) Effects of different concentrations of BMSCs-Exos (0, 109, 1010, 1011 and 1012 events/μL) on the proliferation of CSCPs and chondrocytes. The expression of Collagen II, SOX9 and Aggrecan proteins (E, G) and genes (F, H) in CSCPs and chondrocytes treated with different concentrations of BMSCs-Exos. *, ** and *** indicate p < 0.05, p < 0.01 and p < 0.001, respectively.