Vein/Nerve Microtissue Hybrid Scaffold Repair Of Sciatic Nerve Defect

Objective: Peripheral nerve injury is a common disease in clinic.At present,autologous nerve transplantation is the gold standard for the clinical treatment of peripheral nerve defects.But there are some deficiencies in this method,such as the limitation of donor nerve,the damage of donor area and the mismatch of nerve diameter.Therefore,finding a suitable peripheral nerve defect material has become a research focus.In this study,a novel tissue-engineered nerve graft was constructed based on nerve microtissues combined with vein grafts to repair sciatic nerve defects in rats,and its effectiveness was evaluated.Methods: A novel tissue-engineered nerve graft was constructed by taking the sciatic nerve of rats and preparing it as nerve microtissues and inserting it into the vein graft.Nerve microtissues were cultured in vitro,and were detected by immunofluorescence staining and ELISA.Nerve microtissue were cultured with Schwann cells(SCs)and Dorsal root ganglion(DRG)and observed the influence of it to SCs and DRG.In vivo,the rat sciatic nerve 10 mm long defect model was established and randomly divided into three groups(n=8),Vein group,Microtissue group and Autograft group.12 weeks after surgery,ultrasonic diagnosis,nerve electrophysiology,gait analysis,function evaluation of sciatic nerve,histological analysis and recovery rate of gastrocnemius muscle were used to evaluate the effect of nerve repair.Results: Nerve microtissues can proliferate a large number of Schwann cells and secrete a large number of nerve growth factors,which can promote SCs proliferation and DRG axon growth.At 12 weeks,the average diameter of the Microtissue group was larger than that of the Vein group.Meanwhile,the results of the Microtissue group were significantly better than that of the Vein group in terms of nerve electrophysiology,gait analysis,function evaluation of sciatic nerve,histological analysis and recovery rate of gastrocnemius muscle.Conclusion: Nerve microtissues can proliferate a large number of Schwann cells and nerve growth factors to promote the growth of SCs and DRG.Meanwhile,vein composite nerve microtissues can be constructed into a new tissue-engineered nerve graft that can effectively repair peripheral nerve defects in rats.