几丁糖与聚乳酸合成生物材料修复周围神经缺损

背景：单纯几丁糖材料制成的神经导管机械强度较差，易于塌陷，不利于再生神经的生长。 目的：观察几丁糖与聚乳酸复合物修复大鼠周围神经缺损的可行性。 方法：取30只SD大鼠，制作单侧坐骨神经缺损模型，随机均分为3组，分别采用自体神经、硅胶导管及几丁糖与聚乳酸复合导管修复神经缺损，修复后12周，观察桥接神经外观、表面粘连情况及有无神经瘤生成等，检测大鼠神经传导速度、动作电位波幅及潜伏期，苏木精-伊红染色观察坐骨神经桥接物中段神经再生轴突数量及再生神经横截面积，称量大鼠完整小腿三头肌湿质量。 结果与结论：修复后12周，3组再生神经均通过5 mm神经缺损间隙，硅胶管组形成神经瘤，其余两组均未出现神经瘤；自体神经组再生神经直径大于几丁糖-聚乳酸组、硅胶管组(P < 0.05)，几丁糖-聚乳酸组再生神经直径大于硅胶管组(P < 0.05)；几丁糖-聚乳酸组、自体神经组可见排列整齐的高密度再生轴突，再生轴突数量多于硅胶管组(P < 0.05)，且神经传导速度、动作电位波幅、小腿三头肌湿质量显著大于硅胶管组(P < 0.05)，潜伏期低于硅胶管组(P < 0.05)。表明几丁糖-聚乳酸复合导管可促进缺损周围神经的再生。  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Chitosan/polylactic acid complex for repair of peripheral nerve defects

BACKGROUND:The mechanical strength of nerve conduits made by chitosan is poor and easy to collapse, which is not conducive to the nerve regeneration. OBJECTIVE:To explore the feasibility of chitosan/polylactic acid complex in the repair of peripheral nerve defects in rats. METHODS:Thirty Sprague-Dawley rats were enrolled to establish models of unilateral sciatic nerve defects, and then randomly divided into three groups: autologous nerve, silicone catheter and chitosan/polylactic acid complex were used for defect repair in the three groups, respectively. At 12 weeks after operation, appearance of bridged nerves, surface adhesion, formation of neuroma were observed; nerve conduction velocity, action potential amplitude and latent period were determined; hematoxylin-eosin staining was performed to observe the number of regenerated axons and area of regenerated nerves; wet weight of the complete triceps surae was measured. RESULTS AND CONCLUSION:At 12 weeks after repair, the regenerated nerves in the three groups all passed  through the 5 mm nerve defect gaps, and neuroma only formed in the silicone catheter group. The diameter of regenerated nerves in the three groups was ranked as follows: autologous nerve group > chitosan/polylactic acid group > silicone catheter group (P < 0.05). High-density regenerated axons neatly arranged in the autologous nerve and chitosan/polylactic acid groups, and the number of regenerated axons was higher than that in the silicone catheter group (P < 0.05). Moreover, the nerve conduction velocity, action potential amplitude and wet weight of the complete triceps surae were significantly higher in the autologous nerve and chitosan/polylactic acid groups than in the silicone catheter group (P < 0.05), but the latent period was lower than that in the silicone catheter group (P < 0.05). These findings indicate that the chitosan/polylactic acid conduits can promote peripheral nerve regeneration.