Fig. 4.

MTT assay showing the cell viability of BMSCs cultivated with different concentrations of drug-free microspheres or 25OHD-loaded microspheres. Data represent the mean ± SD (n = 3). *P < 0.05; ** P < 0.01 vs. the DPV2.5 group g. There was no significant difference among the groups with different concentrations of drug-free microspheres and no significant difference between the DPW group and any group with drug-free microspheres. Photographs represent the BMSCs of the N group a, DPF2.5 group b, DPF3.5 group c, DPW group d, DPV2.5 group e, and DPV3.5 group f