人发角蛋白丝束修复大鼠坐骨神经损伤的实验研究

Mophological study of repairing sciatic nerve damage with human hair keratin

目的: 观察人发角蛋白(HHK)丝束桥接体诱导坐骨神经再生过程中形态学变化。方法: 制备坐骨神经损伤SD大鼠动物模型,分别植入HHK或HHK+胶原屏障膜,术后2d、2、3、6、9、12周行组织学观察。结果: 术后2d到2周,断端的施万细胞去分化,沿着HHK束表面纵向分裂增殖。术后3周HHK开始降解,施万细胞大量增生。HHK周围有很多巨噬细胞和多核巨细胞,并出现轴突和大量微血管。术后6周,HHK丝周围可见大量新生的神经纤维。术后9周,HHK降解显著,有明显的神经外膜和束膜。术后12周,HHK完全降解,其部位被新的神经纤维取代。HHK丝束+胶原膜屏障膜组与HHK丝束组没有明显区别。结论: HHK具有良好的桥接作用,坐骨神经沿着HHK再生时在其外周就能由微血管和结缔组织形成一屏障膜,无需外加屏障膜。

Objective: To evaluate the effect of tissue engineeeing artificial nerve made of human hair keratin (HHK) in repairing injured peripheral nerve. Methods: To prepare the model of sciatic nerve damage by transecting to creat a 10mm gap, and implant the HHK or HHK and collegen membrane into it . Anatomic and histological examinations were performed at different time points after surgery. Results: 2 days to 2 weeks after HHK implantation, the Schwann cells dedifferentiated and proliferated along the HHK. 3 weeks after HHK implantation,there were large amount of macrophages and megakaryocytes surrounded the HHK, and a large amount of regenerated Schwann cells and blood vessles were observed between the HHKs which was partially degraded and absorbed. 6 weeks after HHK implantation, there were plenty of inmature Schwann cells in the nerve closed to the surgery site, and some HHKs were degraded completely. 9 weeks after the HHK implantation, HHK degraded apparently. 12 weeks after the operation, almost all HHKs completely degraded, the severed sciatic nerves were perfectly repaired, while Schwann cell proliferated and myelinizated around HHK ,there were nerve fibrils in the myelin. Conclusions: As an ideal material for nerve injury repair, HHK tissue engineering nerve can guide sciatic nerve elongation across a 10mm gap. We discover that an ideal internal environment was formed along the HHK despite of using a collagen membrane.