可降解材料对外周神经的毒性作用研究

目的 研究聚乳酸、聚羟基乙酸和壳聚糖等可降解材料对正常外周神经有无毒性作用，为研制组织工程化神经筛选相容性好的支架材料。方法 取15只SD大鼠，随机分成3组，打开坐骨神经外膜后，分别将聚乳酸、聚羟基乙酸和壳聚糖植入神经束之间。术后7周取材，观察坐骨神经组织结构的变化以及材料在神经组织内引起的异物反应。结果各组的神经干内均有纤维结缔组织轻度增生，但神经束的形态结构无明显变化；各种材料周围均有纤维假膜形成，假膜内有淋巴细胞和巨噬细胞浸润，而包裹壳聚糖的假膜最厚，细胞浸润最明显。结论 聚乳酸、聚羟基乙酸和壳聚糖对外周神经均无毒性，可作为组织工程化神经的支架材料，但壳聚糖引起的异物反应较聚乳酸和聚羟基乙酸明显。

Study of toxic effect of degradable polymers on peripheral nerve

Objective Investigate the toxicity of polylactic acid,polyglacolic acid and chitosan on peripheral nerves,so as to detect the polymers with good biocompatibility to fabricate the scaffold of tissue engineered nerve Method Fifteen Sprague Dawley rats were divided into 3 groups randomly;polylactic acid,polyglacolic acid and chitosan were implanted into the sciatic nerves respectively.7 weeks later,the nerves with polymers were harvested and inspected by macroscopy and light microscope. Results There was mild hypertrophy of fibrous connective tissue within the nerves in each group.However,the nerve fibers were intact The polymers were surrounded by a pseudocapsule,and lymphocytes and macrophages infiltrated.The pseudocapsule coating chitosan was the thickest. Conclusion polylactic acid, polyglacolic acid and chitosan have no toxic effect on peripheral nerves.