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

描述（由申请人提供）：一种新型的生物工程技术，用于快速和永久修复切断的PNS神经。我们的长期目标是将性能优化转化为临床应用，我们的新型和创新技术可以快速和永久修复急性和慢性切断的哺乳动物PNS轴突，以恢复它们在切断之前介导的行为功能。我们使用含有聚乙二醇（PEG）和各种抗氧化剂或氧化剂的生物工程溶液序列，快速和永久地重新连接（PEG-fuse）完全切断的大鼠坐骨轴突末端，作为体内系统模型，使PEG-fuse融合的轴突在生理和形态上完整地通过损伤部位，其刺激恢复完整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学测量是通过病变部位的动作电位传导和轴突内染料扩散以及EM和免疫组织化学分析。我们采用足部断层不对称测试和坐骨功能指数来测量行为恢复。我们通过冷却或环孢素A延缓沃勒氏变性，然后通过peg融合修复慢性切断的轴突长达10天。我们优化了急性或慢性切除的坐骨神经段的组织（生物相容性）反应，这些坐骨神经段被用作位置间自体移植物或同种异体移植物来修复急性或慢性切断的大鼠坐骨神经。神经断裂是人类PNS轴突常见的外伤性损伤。目前，各种各样的治疗方法略微提高了切断后重建连接的PNS轴突的数量和特异性，但没有提高PNS轴突重建这些连接的生长速度（~1mm/天）或时间（几周到几年）。靶组织可能在神经再支配发生前萎缩。因此，靶组织通常是非特异性的再神经支配，行为恢复通常很差。peg融合显著提高了哺乳动物PNS轴突急性切断或挤压断裂后行为恢复的速度和效果。我们还可以将切断的哺乳动物轴突的轴突沃勒氏变性延缓10天，以增加分离后10天内peg融合成功的时间，从而使神经损伤不必立即治疗。我们精心设计的生物工程解决方案和peg融合所需的材料序列只使用fda批准的化学品。因此，我们在大鼠坐骨神经上开发的peg融合技术作为体内系统模型应该迅速转化为临床程序。我们提出的R-01的结果很有可能将当前研究和临床实践的重点从设计提高慢轴突生长结果的程序转移到考虑通过我们的新型peg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.