新型有序排列复合磁性纳米微粒聚己内酯纤维神经导管促周围神经损伤修复的研究

A novel ordered arrangement of composite magnetic nanoparticle polycaprolactone fibrous nerve conduits for peripheral nerve injury repair

目的探讨新型有序排列复合磁性纳米微粒聚己内酯(PCL)纤维神经导管促进周围神经损伤修复的效果。方法通过电纺丝技术制备复合四氧化三铁纳米微粒的PCL神经导管,对比分析四氧化三铁纳米微粒在神经损伤修复中的作用。首先制备含有或不含有四氧化三铁纳米微粒的神经纤维导管,并使用扫描电镜、原子力学电镜分析两种神经导管的力学性质。将28只雄性SD大鼠随机分为空白对照组、单纯无序PCL神经导管组、单纯有序PCL神经导管组和复合磁性纳米微粒有序PCL神经导管组,每组7只,分别进行12 mm坐骨神经缺损手术,空白对照组不进行特殊处理,对不同导管组的神经导管进行缝合,通过HE染色观察神经修复能力,通过坐骨神经功能指数和腓肠肌染色分析其功能恢复情况。结果原子力学电镜结果显示,含有四氧化三铁纳米微粒神经导管表面更为粗糙,更有利于神经轴突的黏附和生长。扫描电镜结果能明显观察到PCL纤维神经导管的有序排列结构,为神经的定向生长提供了适宜的生长环境。在体内神经修复实验中,复合四氧化三铁纳米微粒的有序神经导管组的功能学评分和组织学修复效果显著优于空白对照组(P<0.01)、单纯无序PCL神经导管组(P<0.01)和单纯有序PCL神经导管组(P<0.05)。结论复合磁性纳米微粒的有序PCL纤维能有效促神经轴突有序生长、加速神经损伤修复。

Objective To explore the effect of a novel ordered arrangement of composite magnetic nanoparticle polycaprolactone(PCL)fibrous nerve conduits for peripheral nerve injury repair.Methods The PCL nerve conduits with composite Fe_(3)O_(4)nanoparticles were prepared by electrospinning technique to comparatively analyze the role of Fe_(3)O_(4)nanoparticles in nerve injury repair.Nerve fibrous conduits with or without Fe_(3)O_(4)nanoparticles were first prepared,and the mechanical properties of the two kinds of nerve conduits were analyzed by scanning electron microscopy and atomic force microscopy.Twenty-eight male SD rats were randomly divided into blank control group,simple disordered PCL nerve conduit group,simple ordered PCL nerve conduit group and compound magnetic nanoparticles ordered PCL nerve conduit group,with 7 rats in each group,and they were operated on 12-mm sciatic nerve defects,respectively.No special treatment was given to blank control group,and nerve conduits in different conduit groups were sutured.Nerve repair ability was observed by HE staining,and the functional recovery was analyzed by sciatic functional index and gastrocnemius staining.Results The results of atomic force microscopy showed that the surface of the nerve conduits containing Fe_(3)O_(4)nanoparticles was rougher and more conducive to the adhesion and growth of nerve axons.The results of scanning electron microscopy showed that the orderly structure of PCL fibrous nerve conduits was obviously observed,which provided a suitable growth environment for the directional growth of nerves.In the in vivo nerve repair experiment,the functional scores and histological repair effects of the ordered nerve conduit group combined with composite Fe 3 O 4 nanoparticles were significantly better than those of the blank control group(P<0.01),simple disordered PCL nerve conduit group(P<0.01)and simple ordered PCL nerve conduit group(P<0.05).Conclusion The ordered PCL fibers with magnetic nanoparticles can effectively promote the orderly growth of nerve axons and accelerate nerve injury repair.