Fig. 3

Effects of MSCs-Exo and F-MSCs-Exo on the synthesis and metabolism of cartilage extracellular matrix in vitro. (A, B) Western blot analysis was performed to detect the impact of MSCs-Exo and F-MSCs-Exo on cartilage extracellular matrix synthesis and metabolism markers. (C) ELISA kits were used to measure the levels of Collagen II, Aggrecan, MMP-13, and ADAMTS-4 in the cell culture supernatant. (D) Cartilage extracellular matrix was directly visualized using toluidine blue staining (scale bar = 200 μm). (E ,F) The expression of Collagen II was quantitatively analyzed using immunofluorescence staining and ImageJ software (scale bar = 10 μm). (G, H) The expression of MMP-13 was quantitatively analyzed using immunofluorescence staining and ImageJ software (scale bar = 20 μm). (ns, no significant difference; *p < 0.05; **p < 0.01; ***p < 0.001; n = 3)