Figure 4: The effect of EVs on the proliferation, apoptosis and osteogenesis of MSCs.

(A) The proliferation of MSCs cultured in the presence of graded concentrations of EVs or PBS (control), n = 5. (B) Representative images of TUNEL assay. (C) Quantitative analysis of the percentage of TUNEL-positive cells. Three replicated slides for each group and five randomly selected views from each slide were analyzed, *p < 0.05. (D) qRT-PCR analysis of gene expression for Runx2, OPN, and OCN. Experiments were carried out on three samples for each group. NS, not significant at the level of 0.05.