【摘要】 背景:有关自体神经和聚乳酸-羟基乙酸导管移植修复坐骨神经损伤后的拉伸、应力松弛力学特性测试鲜有报道。目的:对比分析自体神经和聚乳酸-羟基乙酸导管移植修复坐骨神经损伤后的拉伸、应力松弛力学特性。方法:取死后24 h内的新鲜人尸体坐骨神经标本60条,加工成长35 mm试样,分为3组,正常对照组不做任何处理,人工导管移植组、自体神经移植组切断坐骨神经标本,形成20 mm缺损,分别以聚乳酸-羟基乙酸人工导管、自体神经吻接修复,3组均进行拉伸和应力松弛测试。结果与结论:1各组坐骨神经试样应力最初600 s下降较快,600 s后下降缓慢,7 200 s时应力松弛曲线接近水平,各组坐骨神经试样的应力松弛曲线为对数关系变化趋势;2自体神经移植组、人工导管移植组拉伸弹性限度载荷、弹性限度应力、最大载荷、最大应力、弹性限度应变、最大应变小于正常对照组(P<0.05),人工导管移植组拉伸弹性限度载荷、弹性限度应力、最大载荷、最大应力、弹性限度应变、最大应变大于自体神经移植组(P<0.05);3结果表明,聚乳酸-羟基乙酸人工导管具有很好的拉伸和应力松弛力学特性,符合坐骨神经损伤移植修复生物材料的拉伸力学特性和应力松弛力学特性要求。更多还原

【Abstract】 BACKGROUND: The tensile and stress-relaxation mechanical properties of sciatic nerve injury after repaired with autologous nerve and poly(lactic acid-glycolic acid)(PLGA) scaffold are rarely reported. OBJECTIVE: To analyze the tensile and stress relaxation characteristics of sciatic nerve injury after the transplantation of autologous nerve and PLGA scaffold.METHODS: Sixty sciatic nerves were extracted from the fresh cadavers dead within 24 hours, processed into 35 mm samples, and were then randomly divided into three groups. The nerve samples in control group received no intervention; the nerves in artificial and autologous groups were modeled into 20 mm defects, followed by repaired with PLGA scaffold and autologous nerve, respectively. Afterwards, the tension and stress-relaxation tests were performed in each group. RESULTS AND CONCLUSION: The stress in each group descended fast at the first 600 seconds, then descended slowly and was closed to the horizontal level until 7 200 seconds, and the stress-relaxation curves in each group were in logarithmic decrease. The order of the elastic limit load, elastic limit stress, maximum load, maximum stress, elastic limit strain and maximum strain during tension was as follows: control group > artificial group > autologous group(P < 0.05). Our results indicate that the PLGA scaffold holds good tension and stress-relaxation properties, which meets the mechanical requirements of the biomaterials used for sciatic nerve repair.更多还原