复合bFGF及肝素的外周神经桥接体在神经修复中的作用

The Effect of Nerve bridges Consisting of bFGF and Heparin in Repairing Nerves Gaps

目的:探讨bFGF和肝素与外周神经桥接体复合后在兔正中神经缺损修复中的作用。方法:成年雄性新西兰兔48只,建立左侧上臂正中神经30mm缺损。随机分为4组,分别用不同神经桥接体修复神经缺损,即A组为去细胞基膜管种植雪旺细胞并复合bFGF及肝素的桥接体、B组为去细胞基膜管种植雪旺细胞的桥接体、C组为去细胞基膜管复合bFGF及Hep桥接体、D组为自体神经作为对照。于术后1月、3月分别取材行HE及Masson’s三色染色,光镜观察神经再生、神经内胶原纤维形成及血管形成;3月检测各组桥接体运动神经传导速度,并行透射电镜检查,称量指浅屈肌肌肉湿重,观察神经功能恢复。结果:复合bFGF及肝素的桥接体组(A组、C组)神经再血管化及神经胶原形成与自体神经差异无统计学意义(P>0.05),与B组比差异有显著统计学意义(P<0.01)。A组神经再生数据(再生有髓神经纤维密度、平均髓鞘厚度、有髓纤维直径及运动神经传导速度、肌肉湿重恢复率)与自体神经移植(D组)比较,差异无统计学意义(P>0.05)。结论:bFGF及肝素用于组织工程神经桥接体修复神经缺损,能提高神经桥接体再血管化水平,减少胶原纤维形成,促进轴突生长有利于神经再生质量的提高。

Objective：To investigate the function of bFGF and heparin compounding within nerve bridges in repairing rabbit median nerve defects.Methods：48 adult male New Zealand rabbits were randomly divided into four groups （group A,B,C and D）. The models of injured median nerve of 30mm gap were created and repaired by various nerve bridges, which were composed of acellular nerve basal lamina tube, neonatal schwann cells and bFGF and heparin in group A; basal lamina tube and neonatal schwann cells in group B; and exogenous bFGFF,heparin and basal lamina tube bridges in group C. Group D that used autologous nerve grafts served as control. In one and three months after operation, the regeneration, collagen formation and revascularization in each nerve bridge were observed by histological examination, including hematoxylin - eosin staining and Masson＇ s stains. The electrophysiological test, transmission electron microscopy, morphologic analysis, and muscle wet weight and nerve functional recovery were also carried out and evaluated with in 3 months. Results：The bridges in groupA and group C became well vascularizion and had less collagen fibrosis than that in group B （ P 〈 0.0 ）, but no statistic difference comparing with group D（ P 〉 0. 05）. The parameters of group A, including the density of regenerative myelinated fibers, diameter of myelinated fibers, thickness of myelin sheath, the motor nerve conduction velocity and muscle wet weight, were not statistical difference comparing with those of control group （ P 〉 0. 05）. Conclusion： bFGF and heparin could improve nerve regeneration by inducing revascularization of the tissue engineering nerve bridge, enhancing the growth of axons and decreasing the formation of collagen fibrosis.