Evaluation of the Functional Recovery in Sciatic Nerve Injury following the Co-transplantation of Schwann and Bone Marrow Stromal Stem Cells in Rat

INTRODUCTION Transplantation of bone marrow stromal cells (BMSCs) or Schwann cells (SCs) can increase axonal regeneration in peripheral nerve injuries. Based on our previous investigations, the goal of the present work was to examine the individual and synergistic effects of the two different cell types in sciatic nerve injury. We pursued to evaluate the effects of BMSCs and SCs co-transplantation on the functional recovery after sciatic nerve injury in rat. METHODS In this experimental research, adult male Wistar rats (n = 32, 250-300g) were used, BMSCs and SCs were cultured, and the SCs were confirmed with anti S100 antibody. Rats were randomly divided into 4 groups (n = 8 in each group): 1-control group: silicon tube filled with fibrin gel without cells; 2-BMSCs group: silicon tube filled with fibrin gel seeded with BMSCs; 3-SCs group: silicon tube filled with fibrin gel seeded with SCs and 4-co-transplantation group: silicone tube filled with fibrin gel seeded with BMSCs and SCs. The left sciatic nerve was exposed, a 10 mm segment removed, and a silicone tube interposed into this nerve gap. BMSCs and SCs were transplanted separately or in combination into the gap. BMSCs were labeled with anti-BrdU and SCs were labeled with DiI. After 12 weeks electromyographic and functional assessments were performed and analyzed by one-way analysis of variance (ANOVA). RESULTS Electromyographic and functional assessments showed a significant difference between the experimental groups and controls. Electromyography measures were significantly more favourable in SCs transplantation group as compared to BMSCs transplantation and co-transplantation groups (p < 0.05). Functional assessments showed no statistically significant difference among the BMSCs, SCs and co-transplantation groups (p < 0.05). DISCUSSION Transplantation of BMSCs and SCs separately or in combination have the potential to generate functional recovery after sciatic nerve injury in rat. The electromyography evaluation showed a greater improvement after SCs transplantation than BMSCs or the co-transplantation of BMSCs and SCs.