定向纤维蛋白水凝胶多分支支架复合聚乙二醇凝胶修复兔全面神经缺损的实验研究

摘要

目的 探索定向纤维蛋白水凝胶(aligned fibrin hydrogel,AFG)多分支支架复合聚乙二醇(polyethylene glycol,PEG)凝胶修复全面神经缺损的可行性.方法 将12只新西兰大白兔随机均分为3组:AFG-PEG组、AFG 组和自体神经组.3组动物均制造出面神经主干长3 mm、各分支长7 mm的全面神经缺损模型.AFG-PEG组将覆盖了PEG凝胶的AFG多分支支架植入全面神经缺损部位后,再用PEG凝胶覆盖支架与神经断端的连接处;AFG组采用AFG多分支支架桥接全面神经缺损部位;自体神经组将切除的自体全面神经复位缝合.术后1、6及12周对3组动物进行大体观察.术后12周取材,对各组移植物的主干以及上颊支和颧支的不同部位的组织样本进行组织学检测.结果 12只动物术后均存活,术区未见化脓及排异现象.AFG-PEG组的上颊支神经再生情况优于AFG组,该组靠近分叉方向的颧支部分有轴突再生;AFG组的材料降解程度较AFG-PEG组严重,该组上颊支和颧支的神经再生情况均很差;AFG-PEG组和AFG组的神经再生情况均差于自体神经组.结论 AFG可定向引导轴突再生,但由于其降解速度较神经再生速度快,复合PEG凝胶的AFG多分支支架以及单独的AFG多分支支架均不能很好地修复全面神经缺损.%Objective To explore the feasibility of the multi-branch aligned fibrin hydrogel scaffold covered with PEG gel for repair of whole rabbit facial nerve defects.Methods Totally 12 New Zealand white rabbits were randomly divided into 3 groups:the AFG-PEG group (n =4),the AFG group (n =4) and the autologous nerve group (n =4).The models of whole rabbit facial nerve defects were established in all groups.The multi-branch AFG scaffolds covered with PEG gel were implanted to the location of the nerve defects in the AFG-PEG group.The multi-branch AFG scaffolds were implanted to the location of the nerve defects in the AFG group.Reset the autologous nerves,and suture epineurium end to end in the autologous nerve group.At 1,6 and 12 weeks after operation,the animals in 3 groups were observed generally.At 12 weeks after operation,2mm-long samples from the main trunk,superior buccal branch and zygomatic branch of facial nerves at the implant side were got for detection in each group.Results All rabbits survived after surgery,without suppuration or foreign body removed at the surgical site.The nerve regeneration situation of superior buccal branch in the AFG-PEG group was much better than that in the AFG group.Axon regeneration of zygomatic branch could be found near the crotch of grafts in the AFG-PEG group.The degradation of AFG in the AFG group was worse than that in the AFG-PEG group.The nerve regeneration situation of superior buccal branch and zygomatic branch in the AFG group was worse than that in the AFG-PEG group.The nerve regeneration in the autologous nerve group was better than that in the other groups.Conclusion While AFG can help directional axon growth,neither AFG combined with PEG gel nor AFG alone can repair the defects of whole rabbit facial nerve well because the speed of AFG degradation is faster than that of nerve regeneration.