PMMA-induced biofilm promotes Schwann cells migration and proliferation mediated by EGF/Tnc/FN1 to improve sciatic nerve defect

Objective: The purpose of this study is to investigate the role of PMMA-induced biofilm in nerve regeneration compared with silicone-induced biofilm involved in the mechanism.

Methods: PMMA or silicon rods were placed next to the sciatic nerve to induce a biological membrane which was assayed by PCR, Western blot, immunohistochemistry, immunofluorescence and proteomics. A 10 mm sciatic nerve gaps were repaired with the autologous nerve wrapped in an induced biological membrane. The repair effects were observed through general observation, functional evaluation of nerve regeneration, ultrasound examination, neural electrophysiology, the wet weight ratio of bilateral pretibial muscle and histological evaluation. Cell proliferation and migration of Schwann cells co-cultured with EGF-treated fibroblasts combined with siRNA were investigated.

Results: The results indicated that expression of GDNF, NGF and VEGF along with neovascularization was similar in the silicone and PMMA group and as the highest at 6 weeks after operation. Nerve injury repair mediated by toluidine blue and S100β/NF200 expression, the sensory and motor function evaluation, ultrasound, target organ muscle wet-weight ratio, percentage of collagen fiber, electromyography and histochemical staining were not different between the two groups and better than blank group. EGF-treated fibroblasts promoted proliferation and migration may be Tnc expression dependently.

Conclusion: Our study suggested that PMMA similar to silicon induced biofilm may promote autogenous nerve transplantation to repair nerve defects through EGF/Tnc/FN1 to increase Schwann cells proliferation and migration.