人羊膜修复急性坐骨神经损伤模型大鼠

Human amniotic membrane repairs acute sciatic nerve injury in rat models

背景:人羊膜具有免疫原性低、可以减少瘢痕形成、抑制炎性反应、抗血管生成等作用。目的:观察人羊膜对坐骨神经急性损伤修复与再生的作用。方法:选用成年雌性SD大鼠(河北医科大学实验动物中心提供)90只,制备坐骨神经急性损伤模型,随机分为羊膜组、几丁糖组、空白对照组,每组30只。羊膜组坐骨神经损伤处用新鲜羊膜包裹,羊膜两端各缝合1针固定;几丁糖组坐骨神经损伤处近端用9-0无创缝线做标记,损伤神经周围注入约0.5mL医用几丁糖凝胶;空白对照组坐骨神经钳夹处近端用9-0无创缝线做标记,不用任何材料处理。术后进行大体、光镜、透射电镜观察以及轴突图像分析和神经电生理检测。结果与结论:(1)大体、光镜、透射电镜观察显示:与空白对照组相比,羊膜组大鼠术后肢体肿胀较轻,神经充血水肿轻,与周围组织粘连轻,炎性反应小,成纤维细胞及新生血管少,许旺细胞内细胞器增生活跃,成纤维细胞及胶原产生少,修复时程短,与几丁糖组差别不大;(2)轴突图像分析显示:羊膜组和几丁糖组髓鞘厚度及有髓纤维直径大于空白对照组(P<0.05);(3)神经电生理检测显示:3组神经传导速度比较无明显差异,3组之间波幅比较差异均有显著性意义(P<0.05),羊膜组和几丁糖组潜伏期均短于空白对照组(P<0.05);(4)结果表明,羊膜可为神经修复提供相对稳定微环境,减少粘连,抑制炎性反应,促进神经修复与再生,获得较好的治疗效果。羊膜在体内存留时间长,有利于神经再生和微环境的维持,利于神经再生与功能恢复,羊膜要优于几丁糖。

BACKGROUND: Human amniotic membrane with low immunogenicity can reduce scar formation, inhibit inflammation and prevent angiogenesis. OBJECTIVE: To observe the effect of human amniotic membrane on repair and regeneration process after acute nerve injury. METHODS: Ninety adult male Sprague-Dawley rats provided by Laboratory Animal Center of Hebei Medical University were used for establishing the models of acute sciatic nerve injury and then randomly divided into amniotic membrane (nerve entrapment with amniotic membrane), chitosan (nerve entrapment with chitosan gel) and blank control (without any treatment) groups (n=30 per group). Gross, light microscope and transmission electric microscope observations, axon image analysis and electrophysiological examination were performed. RESULTS AND CONCLUSION: Gross, light microscope and transmission electric microscope observations revealed: compared with the blank control group, the mild limb swelling, neurohyperemia, and edema were observed in the amniotic membrane group. In addition, the adhesion with the surrounding tissue was mild in the amniotic membrane group, the inflammatory reaction was mild and there were few fibroblasts and newborn capillaries. In the amniotic membrane group, function of organelles was active, there were few fibroblasts and less collagen, and the repair time was short, which were similar with the chitosan group. The axon image analysis showed that thickness of the myelin sheath and the diameter of myelinated fibers in the amniotic membrane and chitosan groups were superior to those in the blank control group (P < 0.05). Neurophysiological stimulation showed that there was no significant difference in the nerve conduction velocity among groups. The amplitude was significantly different among groups (P < 0.05). The latent period in the amniotic membrane and chitosan groups was significantly shorter than that in the blank control group (P < 0.05). To conclude, amniotic membrane can provide a relatively stable microenvironment for nerve repair, reduce adhesion, inhibit inflammatory reaction, promote the repair and regeneration of nerve, and show good therapeutic effect. Amniotic membrane has a long retention time in vivo, which is beneficial to nerve regeneration and microenvironment maintenance, and contributes to the recovery of nerve function. Therefore, amniotic membrane is better than the chitosan.