The Study Of Silk Fibroin Modified Nanofiber In Neural Tissue Engineering

Objective:poly (L-lactic acid-co-epsilon-caprolactone) (P(LLA-CL)) is a wildly used hydrophobic material. It degrades slowly and has good mechanical properties. Silk fibroin have negatively charged terminus, Which can well contribute to cell attachment with the presence of the tripeptide Arg(R)-Gly(G)-Asp(D). This research is to study the biocompatibility of the silk fibroin modified P(LLA-CL) (P(LLA-CL)-SF) in vitro and the effect of using electrospinning P(LLA-CL)-SF nanofiber repair nerve gap in vivo.Method:The biocompatibility of P(LLA-CL)-SF was studied in vitro and in vivo. In vitro, The MTT Cell Proliferation Assay was used to evaluate the biocompatibility of P(LLA-CL)-SF and Schwann cell. In vivo,5 groups have been set:repairing with augraft (A group), sciatic defect without repair (B group), repairing with P(LLA-CL)-SF scaffold(C group), repairing with P(LLA-CL) scaffold (D group), repairing with Schwann cells on P(LLA-CL)-SF scaffold (E group), repairing with Schwann cells on P(LLA-CL) scaffold (E group). To evaluate the effect of repairing by P(LLA-CL)-SF, the sciatic nerve function index (SFI), the ratio of active potential and amplitude(the operated side/normal side), the wet weight ratio of gastrocnemius muscle (the operated side/normal side), the area ratio of gastrocnemius muscle fiber (the operated side/normal side), nerve conduction velocity, the number and thickness of regenerated nerve are measured on the 2nd,3rd month.Result:In vitro, we observed the MTT of P(LLA-CL)-SF with Schwann cells is better than P(LLA-CL) with Schwann cells. In vivo, the group C and E which used P(LLA-CL)-SF, have repaired better than group D and F, which used P(LLA-CL), in the sciatic nerve function index (SFI), the ratio of active potential and amplitude(the operated side/normal side), the wet weight ratio of gastrocnemius muscle (the operated side/normal side), the area ratio of gastrocnemius muscle fiber (the operated side/normal side), nerve conduction velocity, the number and thickness of regenerated nerve.Conclusion:Therefore, we concluded that P(LLA-CL)-SF have better biocompatibility than P(LLA-CL) and more suitable for nerve regeneration.