Decellularized nerve xenograft combined with lycium barbarum polysaccharide for repair of sciatic nerve defect in rats

Objective To explore the effect of lycium barbarum polysaccharide (LBP) and decellularized nerve xenograft combination on nerve regeneration and recovery in repairing rat sciatic nerve defects. Methods Xenogeneic acellular nerve scaffolds were prepared by chemical extraction of tibial nerves from rabbits. A 10 mm left sciatic nerve defect model was created in 90 healthy adult Sprague-Dawley rats who were randomly divided into 5 groups: blank group (n=18), model group (n=18), LBP group (n=18), scaffold group (n=18), LBP and scaffold combination group (n=18). Two weeks after model creation. The sciatic nerve defect in LBP, scaffold and combination groups was repaired either by LBP, by scaffold, or by the LBP xenograft combination. After the second surgery, the rats survived for 4, 8 and 12 weeks, respectively. Gross observation of the scaffold, nerve conduction study to measure sciatic nerve motor nerve conduction velocity (MNCV), and neuromorphometry analysis of the graft were carried out at these three time points. Results Neuroma formation at the proximal nerve end was observed in the model group and LBP group. Adhesion of nerve ends to the surrounding tissue was more severe in the model group than in the LBP group. The sizes of the nerve grafts in the scaffold group and combination group were comparable. Proficient vascularization on the surface of these grafts was seen. There was only slight adhesion to the surrounding tissue. The regenerated nerve fibers in the combination group were denser and better oriented. Motor nerve conduction velocity recovery and the number of myelinated nerve fibers in the grafts were measured at 12 weeks postoperatively for blank, model, LBP, scaffold and combination groups, respectively. The differences among the groups were significant (P<0.05). Conclusion The combination of LBP and xenogeneic acellular nerve scaffold enhances peripheral nerve regeneration and recovery when used to repair nerve defects. Key words: Sciatic nerve; Nerve regeneration; Xenogeneic acellular nerve scaffold; Lycium barbarum polysaccharide