In vitro cytotoxicity, cell regeneration and angiogenesis effects of MN-MgH2. a) Cell viability of fibroblasts after 72-h treatment with MN-PLGA extract, MN-MgH2 extract or normal cell culture medium (control group). b) Cell viability of fibroblasts after treated with varied concentrations of MgH2 for 72 h. c) Confocal images of migrated HUVECs in Transwell experiment after 24-h treatment with MN-PLGA extract, MN-MgH2 extract, MgH2 solution or normal cell culture medium (control group). Nucleus was stained with Hoechst (cyan). d) Quantification result of migration rate of HUVECs in Transwell experiment after different treatments for 24 h, which is corresponding to the images presented in (c). e) Fibroblasts migration evaluated using cell migration assay after different treatments for 24 h. f) Quantification of the gap closure ratio in each group, which is corresponding to the images presented in (e). g) Images of HUVECs after 4-h treatment with MN-MgH2 extract, MgH2 solution or normal cell culture medium (control group). h) Quantifications of nodes and tube length in each group. n = 3, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.