Fig. 1

PRP promotes proliferation and osteogenic differentiation of BMP2-modified MSCs in vitro. a Proliferation of MSCs with different PRP concentrations (n = 4). The cell seeding density is 5 × 10⁴ per well in a 96-well plate. MSCs + PRP (10%) group has significantly higher cell proliferation rate at days 1, 3, and 7 as compared with other groups and is indicated by ^* p <0.05. b ALP activity of MSCs, MSCs + BMP2 (MSCs + B2), MSCs + PRP, and MSCs + B2 + PRP. The cells were induced with osteogenic media for 7 days. Data represent the mean ± SD of  3 samples. The ALP activity of MSCs + B2 + PRP group was significantly higher than the other groups as marked as ^** p < 0.01; ^*** p < 0.0001; NS: not statistically significant. c Alizarin Red staining of MSCs, MSCs + B2, MSCs + PRP, and MSCs + B2 + PRP. Cells were cultured in osteogenic medium for 21 days. d Quantitative analysis (n = 5) of cell mineralization from Alizarin Red staining shown in C. ^*** p < 0.0001; NS: not statistically significant. ALP alkaline phosphatase, B2 bone morphogenetic protein 2, MSCs mesenchymal stem cells, nCS nano-calcium sulfate, PRP platelet-rich plasma