S-100 and VEGF immunostaining and IOD value analyses at 12 weeks postoperatively. S-100 immunostaining (A-C, scale bar = 10 μm) and VEGF immunostaining (D-F, scale bar = 20 μm) at 12 weeks postoperatively with SLCs (A and D), BM-MSCs (B and E) and isografts (C and F). The IOD values of the positive expression of S-100 and VEGF in the regenerated nerves (G). The isograft and ANG + SLC groups showed a significantly higher level in both S-100 and VEGF immunostaining compared with the ANG + BM-MSC group. The data were shown as the mean ± SEM. *P <0.05, compared with the ANG + BM-MSC group (n = 15).