Acellular xenogeneic nerve repopulated with BMSCs to repair peripheral nerve defects: an experimental study

Objective To evaluate the outcomes of repairing peripheral nerve defects with acellular xenogeneic nerve (AXN) repopulated with bone marrow stromal cells (BMSCs). Methods Rat BMSCs were cultured in vitro.Right sciatic nerve 10 mm defect model was established in 60 female Wistar rats that were randomly divided into 3 groups,with 20 each.The gaps were repaired using one of the following:AXN repopulated with BMSCs (group A),AXN (group B) and autologous nerve graft (group C).Tissues were harvested 4 and 12 weeks after the operation.The status of BMSCs and axonal regeneration were evaluated by general observation,electrophysiological examination,gastrocnemius muscle fiber measurement,histological observation and scanning electron microscopy (SEM) observation of the regenerating nerve. Results After transplantation viable cells were observed in all the grafts.More cells were noted in group A and C,which were well oriented.BrdU positive expression was seen in S-100 positive cells only in group A.After 12 weeks,regenerating axons had passed the defect.Histological and electrophysiological testing were better in group A and C than in group B ( P ＜ 0.05 ).No significant difference was detected between group A and C ( P ＞ 0.05).Conclusion BMSCs can survive in the body,and can differentiate into SCs.AXN repopulated with BMSCs leads to comparable results to autologous nerve graft when used to repair nerve defects. Key words: Nerve regeneration;  Schwann cells;  Bone marrow stem cells;  Acellular xenogeneic nerve