Fig. 4

sEV-CUR exhibit enhanced chondro-protective effects in TBHP-induced chondrocytes. a Representative EdU staining fluorescence images of curcumin, sEV, or sEV-CUR treated chondrocytes, scale bar: 25 μm; b statistical evaluation of fluorescent positive rate after EdU staining (n = 3); c the chondrocyte proliferative ability in each group was detected and analyzed by CCK8 assay after 2 days treatment of curcumin, sEV, or sEV-CUR (n = 6); d, e relative mRNA expression of chondrocyte anabolism related markers aggrecan and collagen II (n = 3); f, g relative mRNA expression of chondrocyte catabolism related markers ADAMTS5 and MMP13 (n = 3); h, i relative mRNA expression of inflammatory related markers IL-1β and TNFα (n = 3). NS, not significant, *P < 0.05, **P < 0.01, ***P < 0.001