[PEAD:肝素:NGF]生物材料促进大鼠坐骨神经损伤恢复

目的:探讨新型材料poly(ethylene argininylaspartate diglyceride)(PEAD)结合肝素包裹神经生长因子组成的三元复合体比单纯运用NGF治疗大鼠坐骨神经损伤效果明显,为临床治疗外周神经损伤提供实验依据。方法:24只200g左右Wistar大鼠,分成生理盐水组,NGF组,NGF凝聚体三组,每组各8只,距梨状肌下缘远侧约1.5cm处运用静脉夹夹紧坐骨神经2min,采用无创细线(5/0)缝合肌肉和皮肤,并用碘伏进行消毒,NGF组每天沿坐骨切迹肌注80ngNGF,持续30天;NGF凝聚体组仅在造模时肌注复合体(内含2.4μg的NGF);生理盐水组给予等体积的生理盐水。术后每周运用脚步印迹法评价动物的行为学,并于30天后灌流、收集各组损伤侧坐骨神经,运用HE染色及投射电镜观察坐骨神经结构恢复情况,免疫荧光标记MBP,观察其蛋白的表达。结果:NGF组,NGF凝聚体组在行为学、病理结构及蛋白的表达远高于生理盐水组,并且NGF凝聚组的治疗效果优于NGF组。结论:新型凝聚体包载NGF具有明显的促进周围神经损伤后的修复与再生作用,能够在一定程度上提高单纯运用NGF治疗大鼠坐骨神经损伤的不足,达到更加理想和显著的促恢复效果。

Biomaterial of [PEAD: Heparin: NGF] Coacervate Promote Function Recovery of Sciatic Nerve Regeneration in Rats

Purpose:To overcome the defect of nerve growth factor(NGF) in the treatment of sciatic nerve injury. A polycation-poly(argininylaspartate diglyceride ethylene)(PEAD) was designed to substitute the heparin-binding sequence of the FGF receptor and form a ternary complex containing the polycation, heparin and NGF, which provides experimental evidence for the clinical treatment of peripheral nerve injury. Methods:Experiment young adult male Wistar rats aged 8 weeks(200~220 g) were selected and divided randomly into 3 groups:Saline group, Free NGF group and NGF coacervate group with 8 rats in each group. The common sciatic nerve was exposed at the level of the middle of the thigh by blunt dissection through the biceps femoris and moderate contusion injuries were performed using a vascular clip, the skin was then closed with 5-0 stitches. Following surgery, each group was injected equivalent volume saline, free NGF(80 ng/day), or the NGF coacervate containing equivalent NGF in the injury sites of right limb through a 1 ml syringe. At 30 days after surgery, the regenerated rat sciatic nerve was evaluated by footprint analysis, immunohistochemistry and histologic assessment. Experimental data were processed using the statistical software SPSS 13. 0.Results:The behavior, pathological structure and protein expression treated by NGF or NGF coacervate exhibited better than that saline group. Moreover, the therapeutic effect of NGF coacervate group was better than free NGF group. Conclusion:The new type of coacervate loaded with NGF could evident effects on the repair and regeneration of peripheral nerve injury, this may lay the groundwork for future translational studies of NGF coacervate for peripherial nervous system(PNS) diseases, especially those related to sciatic nerve injury.