Membrane Sealing:Biopolymers for Tissue Electroporation

膜密封：用于组织电穿孔的生物聚合物

• 批准号: 6875021
• 负责人: RAPHAEL Carl LEE
• 金额: $ 30.46万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-08-08
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6875021
• 关键词: 3,4 methylenedioxyamphetamine; action potentials; adenosine triphosphate; antioxidants; ascorbate; biopsy; cell membrane; copolymer; electromyography; electrophysiology; electroporation; ethylene oxide; histopathology; injury; intravenous administration; laboratory rabbit; lipid bilayer membrane; membrane fusion; membrane permeability; muscle cells; necrosis; nonhuman therapy evaluation; radiation dosage; radiopharmacology; radiotracer; striated muscles; surfactant

Disruption of the cell membrane lipid bilayer structure is a common cause of tissue necrosis in many illnesses, including high-energy trauma. Loss of membrane ionic barrier function is followed by rapid metabolic energy exhaustion and then acute cellular necrosis. Electrical shock induced tissue injury is superb model for this type of cell injury because membrane damage occurs by electroporation, exposure to high temperatures and possibly high-power acoustic stresses (Appendices I and II). Because of the relatively large size of the cells, skeletal muscle and nerve are especially vulnerable to the direct electrical mechanisms of cellular membrane damage (electroporation and electroconformational protein denaturation). Theoretical, experimental and clinical data all indicate that membrane damage by electroporation is a significant cause of much of the skeletal muscle and nerve injury that results (Appendix II). Our lab and others have shown that poloxamer surfactants (Poloxamer 188 and Poloxamine 1107) reduce acute necrosis mediated by membrane disruption (Appendix III, Sharma et al. 1996, Merchant et al. 1998, Hannig et al. 2000). Thus, we postulate that these surfactants can be used to substantially reduce tissue necrosis following electroporation to result in significantly improved tissue survival and function. We propose to determine how effective intravenous Poloxamer 188 with and without cofactors are in sealing electroporated skeletal muscle cell membranes in vivo and in improving functional recovery. We propose to assess outcomes using quantitative real- time functional assay measurement techniques (surface electromyography and radiopharmaceutical imaging) as well as by standard histological and biochemical markers reflective of membrane integrity and tissue necrosis. Furthermore, on the basis of completed experiments, we postulate that antioxidants (i.e. ascorbate) may protect poloxamers from oxidative degradation to enhance its efficacy, and propose that MgATP will enhance responsiveness to membrane sealing. A basic need also addressed in this proposal is the refinement and calibration of real-time surface electromyography and radiopharmaceutical imaging as tools for quantifying therapeutic responses to membrane sealing therapy and for real-time assessment in clinical studies. Such diagnostic tools would be of tremendous clinical value because rapid detection, discrimination, and localization of tissue injury would accelerate and guide clinical therapy. Although we choose electroporation as the experimental model to test in vivo membrane sealing, these results and experimental methods will be directly relevant to other diseases characterized by membrane permeabilization, e.g. ischemia-reperfusion, freeze-thaw and mechanical trauma.

细胞膜脂质双层结构的破坏是许多疾病（包括高能创伤）的组织坏死的常见原因。 膜离子屏障功能的丧失之后是快速的代谢能耗尽，然后是急性细胞坏死。 电击诱导的组织损伤是这种类型的细胞损伤的绝佳模型，因为膜损伤是通过电穿孔，暴露于高温和可能的高功率声音应力（附录I和II）的。由于细胞的大小相对较大，骨骼肌和神经特别容易受到细胞膜损伤的直接电气机制（电穿孔和电构成蛋白质变性）。理论，实验和临床数据均表明，导致骨骼肌肉和神经损伤的重要原因是导致骨骼肌肉和神经损伤的重要原因（附录II）。 我们的实验室和其他实验室表明，洛毒酸酚表面活性剂（洛洛沙转胺188和洛沙胺1107）减少了膜破坏介导的急性坏死（Appendix III，Sharma等，1996，Merchant等，1998年，Hannig等人，Hannig等人，2000年）。 因此，我们假设这些表面活性剂可用于大大减少电穿孔后的组织坏死，从而显着改善了组织的存活率和功能。我们建议确定带有和没有辅助因子的有效静脉注射恐惧胺188如何在体内密封电骨肌肉细胞膜并改善功能恢复。 我们建议使用定量实时功能测定测量技术（表面肌电图和放射性药物成像）以及标准的组织学和生化标志物来评估结果。 此外，根据完成的实验，我们假设抗氧化剂（即抗坏血酸酯）可以保护洛沙胺免受氧化降解以提高其疗效，并提出MGATP将提高对膜密封的响应能力。该提案中还解决了基本需求，是对实时表面肌电图和放射性药物成像的完善和校准，作为量化对膜密封治疗的治疗反应的工具，并在临床研究中进行实时评估。 这种诊断工具将具有巨大的临床价值，因为快速检测，歧视和组织损伤的定位将加速并指导临床治疗。 尽管我们选择电穿孔作为在体内膜密封测试的实验模型，但这些结果和实验方法将直接与以膜通透性为特征的其他疾病有关，例如缺血 - 重新灌注，冻融和机械创伤。