Fig. 4

TSC-EVs enhanced osteogenic efficacy of MSCs. The ALP activity (A) and calcium content (B) of TSC-EV-treated MSCs were examined on the indicated day. C-H Relative expression levels of osteogenic marker genes in TSC-EV-treated MSCs were determined using quantitative RT-PCR. MSCs cultured with GM were used as controls. Representative image (I) and quantified staining (J) of Alizarin Red S-stained MSCs on day 14 in TSC-EV-treated MSCs compared to OIM. Scale bars, 100 μm. K The synergistic increase in ALP activity in TSC-EV-treated MSCs with additional TSC-CM was analyzed. Error bars represent the mean and SD. (n = 3; *p < 0.05, **p < 0.01, and ***p < 0.001)