The Construction Of Tissue Engineered Nerve With ABBS Modified Nanofiber

Avidin-Biotin Binding System (ABBS), a non-conjugated binding system known by its extraordinarily high affinity, can enhance cells adhesion in tissue engineering. The main object of this study is to investigate the possibility of applying the ABBS in Nano-fiber P(LLA-CL)(75:25) tissue engineering nerve in vitro and in vivoIn vitro, we study the feasibility of ABBS by evaluating the effect of avidin-biotin binding system on Schwann cells adhesion, proliferation, appearance and gene expression. The results show that ABBS could promote the adhesion efficacy, increase the secretion of the extracellular matrix and the gene expression of S100?GDNF?BDNF?NGF?CNTF?PMP22, no adverse effect has been found on SCs metabolism and proliferation.In vivo, we evaluate the effects of ABBS modified Nano-fiber with Schwann cells to repair the sciatic nerve defects in the Wistar rats. All the 60 rats are randomly and equally devided into 5 groups:Group A, autografts repair; Group B, sciatic defect without repair; Group C, repaired by P(LLA-CL) nanofiber without SCs; Group D, repaired by P(LLA-CL) nanofiber with SCs; Group E, ABBS modified P(LLA-CL) nanofiber with SCs. The gait analysis, electrophysiology, muscle weight and cross-sectional area of gastrocnemius, number of regenerated axons and thickness of its myelin sheaths are used to evaluate the efficiency of sciatic nerve regeneration. The results demonstrate that the SFI, electrophysiology, muscle weight, axon quantities and myelin sheath thickness in Goup D and E are appaprently better than those in Group C (P<0.05), but inferior as compared to Group A. The time needed for SCs to completely cover the nanofiber in Group E is much shorter than in Group D (30 min vs.24 hour), but there is no significant differences in the sciatic nerve regeneration between Group D and Group E (P>0.05).Conclusion:ABBS could effectively and rapidly enhance the SCs adhesion strength and speed onto Nano-fiber scaffold, and make SCs completely covering the fiber within a very short time; meanwhile, it can also enhance the gene expression of S100?GDNF?BDNF?NGF?CNTF?PMP22, promote the secretion of extracellular matrix, and have no adverse effect in the sciatic nerve regeneration. ABBS is a practical tool in the tissue engineering nerve, the present study support the application of the ABBS with antibody selecting defferentited SCs to construct tissue engineering nerve.