Fig. 2

Biocompatibility evaluation of BMSCs exposed to C₂S NPs (0, 10, 50, 100 μg/mL). a ICP-MS exploration of ion levels released from C₂S NPs in extracellular fluid for 24 h. b Uptake of C₂S NPs by BMSCs was observed via TEM at 6 h. c Cellular morphology and structures of cell organelles were observed by rhodamine-phalloidin (Green) and DAPI (Blue) staining of BMSCs at different times points (6, 12, and 24 h), scale bar 20 µm. d Cell viability was evaluated using CCK-8 assays at different times points (6, 12, and 24 h). e The levels of LDH release were detected in BMSCs post-treatment with C₂S NPs for 6, 12, and 24 h; f Cells were stained with Annexin V-FITC and PI and analyzed by flow cytometry. Quantification of the cell early and total apoptosis ratio is shown below on the right. Values are expressed as the mean ± SEM n = 3. * p < 0.05, ** p < 0.01, *** p < 0.001 compared with the control group