A novel bioengineered technique to rapidly and permanently repair cut PNS nerves

描述(申请人提供)：一种快速和永久修复切断的PNS神经的新型生物工程技术我们的长期目标是对性能进行优化，以便将我们的创新技术转化为临床使用，从而产生急性和慢性切断的哺乳动物PNS轴突的快速和永久修复，以恢复它们在切断前调节的行为功能。我们应用一系列特定的含有聚乙二醇(PEG)和各种抗氧化剂的生物工程溶液来快速和永久地重新连接(PEG-FUSE)完全切断的大鼠坐骨神经轴突，作为体内系统的模型系统，使得聚乙二醇化融合的轴突在损伤部位生理和形态上是完整的，它们的刺激恢复了由完整的坐骨神经介导的行为功能。我们对轴突连续性的生理和形态测量是动作电位传导和轴突内染料在病变部位的扩散，以及EM和免疫组织化学分析。我们的行为恢复措施是足部故障不对称性测试和坐骨神经功能指数。我们通过冷却或环孢素A延缓沃勒氏变性，然后通过聚乙二醇化融合修复慢性切断的轴突长达10天。我们的性能优化了急性或慢性切除的坐骨神经节段的组织(生物相容性)反应，这些节段用作位置间自体或同种异体移植物，以修复急性或慢性切断的大鼠坐骨神经。神经切断是人类三叉神经节轴突常见的外伤性损伤。目前的各种方法略微改善了切断后重建连接的PNS轴突的数量和特异性，但不能改善PNS轴突重建连接的生长速度(~1 mm/天)或时间(数周至数年)。靶组织可能会在重新神经支配发生之前萎缩。因此，靶组织经常被非特异性地重新神经支配，行为恢复通常很差。聚乙二醇酯融合显著提高了哺乳动物三叉神经节轴突急性切断后行为恢复的速度和效率。我们还可以将切断的哺乳动物轴突的轴突沃勒氏变性延迟长达10天，以增加切断后长达10天的成功聚乙二醇化融合的时间，从而使神经损伤不必立即治疗。我们精心设计的聚乙二醇化所需的生物工程解决方案和材料序列仅使用FDA批准的化学物质。因此，我们在大鼠坐骨神经上开发的聚乙二醇化融合技术作为体内系统的模型，应该会迅速转化为临床程序。我们建议的R-01的结果具有很高的潜力，可以将当前研究和临床实践的重点从设计程序来增强缓慢的轴突生长结果，转向考虑使用我们新的聚乙二醇化融合技术进行快速修复。

DESCRIPTION (provided by applicant): A novel bioengineered technique to rapidly and permanently repair cut PNS nerves Our long term objective is to performance-optimize to translate for clinical use our novel and innovative technique to produce rapid and permanent repair of acutely and chronically severed mammalian PNS axons to restore the behavioral functions they mediated prior to severance. We apply a well-specified sequence of bioengineered solutions containing polyethylene glycol (PEG) and various anti-oxidizing or oxidizing agents to rapidly and permanently rejoin (PEG-fuse) completely cut-severed ends of rat sciatic axons as a model in vivo system so that PEG-fused axons are physiologically and morphologically intact through the lesion site and their stimulation restores behavioral functions mediated by intact sciatic nerves. Our physiological and morphological measures of axonal continuity are action potential conduction and intraaxonal dye diffusion across the lesion site and EM and immuno-histochemical analyses.. Our measures of behavioral restoration are Foot Fault Asymmetry test and Sciatic Functional Index. We retard Wallerian degeneration by cooling or cyclosporin A and then repair axons chronically severed for up 10 days by PEG-fusion. We performance optimize tissue (biocompatability) responses of acutely or chronically excised sciatic nerve segments that are used as inter- position autografts or allografts to PEG-fuse repair acutely or chronically cut rat sciatic nerves. Nerve severance is a common traumatic injury to PNS axons in humans. Various procedures currently slightly improve the number and specificity of PNS axons that reestablish connections following severance, but not outgrowth rate (~1mm/day) or time (weeks to years) for PNS axons to re-establish those connections. Target tissues may atrophy before re-innervation can occur. Consequently, target tissues are often non-specifically re-innervated and behavioral recovery is often poor. PEG-fusion dramatically improves the speed and efficacy of behavioral recovery following acute cut- or crush-severance of mammalian PNS axons. We can also retard axonal Wallerian degeneration of severed mammalian axons for up to 10 days to increase the time for successful PEG-fusion for up to 10 days post-severance so that nerve injuries do not have to be immediately treated. Our well-specified sequence of bio-engineered solutions and materials needed for PEG-fusion use only FDA-approved chemicals. Hence, our PEG-fusion technique developed on rat sciatic nerves as a model in vivo system should rapidly translate to clinical procedures. The results of our proposed R-01 have high potential for shifting the current emphasis of current research and clinical practice from devising procedures to enhance the results of slow axonal outgrowth to considering rapid repair by our novel PEG-fusion technique.