Partial-thickness wound healing via topical ATP delivery

描述(由申请人提供)：我们计划的长期目标是开发安全有效的技术来对抗缺血造成的组织损伤。这项建议的具体目的是调查人类不可愈合的慢性创面中高能磷酸盐的含量，进一步改进我们的细胞内直接能量输送技术，将该技术应用于伤口治疗，并研究细胞内能量供应促进伤口愈合的一些机制。我们的中心假设是高能磷酸盐的消耗是慢性创面无法愈合的根本原因；细胞内直接向创面输送三磷酸腺苷将改善微环境，显著促进愈合过程。我们第一阶段研究的结果还发现：1)取自人类慢性伤口的组织活检显示高能磷酸盐含量显著减少；2)使用VitaSolTM的细胞内ATP输送显著增加兔耳模型中伤口组织的高能磷酸盐含量；以及3)细胞内ATP输送导致极快的颗粒状组织生长。利用微创外科手术方法，我们还开发了一种新的兔缺血创伤模型，该模型首次成功应用于糖尿病动物。第一阶段研究的结果证明了我们的基本概念。这项第二阶段的研究将追求三个目标：1.第一个可检验的假设是创面组织缺氧导致高能磷酸盐利用率降低，这种减少是慢性创面无法愈合的主要原因。终点：人体各种慢性伤口中的高能磷酸盐含量。2.有待检验的第二个假设是，可以大规模生产含有包裹的三磷酸腺苷的单层脂囊，并且这些囊泡可以用于伤口护理，而全身反应很少。终点：一种稳定、冷冻干燥的单层脂泡的特定配方，含有ATP，具有良好的组织渗透性，适合伤口护理，以及一种能够产生这些囊泡的cGMP工艺。3.第三个可检验的假说是，细胞内的ATP递送将增加伤口组织的能量水平，诱导生长因子和其他愈合机制的协同上调，以促进愈合过程。终点：组织高能磷酸盐含量及其与生长因子和愈合速度的关系。上述三个主题在过去都没有被探讨过。该项目的成功和这种新的细胞内能量传递技术的扩大使用可能会对医学产生重大影响。它不仅将改善慢性伤口的护理，还将提高我们治疗各种缺血性疾病的能力，如休克、中风、严重创伤、心脏病发作、脊髓损伤、体外循环、器官移植、急性或慢性肺部疾病以及许多其他涉及缺血的疾病。此二期方案的具体目的是调查人类不可愈合的慢性创面中高能磷酸盐的含量，进一步改进我们的细胞内直接能量输送技术，将该技术应用于伤口治疗，并研究细胞内能量供应促进伤口愈合的一些机制。我们的第一阶段项目改进了我们细胞内ATP递送制剂的配方、包封率和颗粒大小，测量了人类慢性创面的高能磷酸盐含量，并将细胞内ATP递送应用于动物模型。我们的细胞内ATP输送技术导致兔耳伤口内颗粒状组织极快生长。目前项目中概述的任务过去都没有被探索过。该项目的成功和这种新的细胞内能量传递技术的扩大使用可能会对医学产生重大影响。它不仅将改善慢性伤口的护理，还将提高我们治疗各种缺血性疾病的能力，如休克、中风、严重创伤、心脏病发作、脊髓损伤、体外循环、器官移植、急性或慢性肺部疾病以及许多其他涉及缺血的疾病。

DESCRIPTION (provided by applicant): The long-term goal of our program is to develop safe and effective techniques to combat tissue damage caused by ischemia. The specific aims of this proposal are to investigate high-energy phosphate contents in human non-healing chronic wounds, to further improve our direct intracellular energy delivery technique, to use this technique in wound treatment, and to study some of the mechanisms by which intracellular energy supply enhances wound healing. Our central hypotheses are that depletion of high energy phosphate contents is the fundamental cause of non-healing chronic wounds; and that direct intracellular delivery of ATP to the wound will improve the microenvironment and substantially enhance the healing process. Results from our Phase I study also found that: 1) tissue biopsies taken from human chronic wounds showed significantly reduced high-energy phosphate contents; 2) intracellular ATP delivery using VitaSolTM substantially increased wound tissue high-energy phosphate contents in a rabbit ear model; and 3) intracellular ATP delivery caused extremely fast granular tissue growth. Using minimally invasive surgical procedures, we have also developed a new rabbit ischemic wound model that has been used successfully, for the first time, in diabetic animals. Results from the Phase I study have proven our basic concept. Three aims will be pursued in this Phase II study: 1. The first testable hypothesis is that wound tissue hypoxia results in decreased high-energy phosphate availability, and this reduction is the major cause of non-healing in chronic wounds. End point: high-energy phosphate contents in various chronic human wounds. 2. The second hypotheses to be tested is that unilamellar lipid vesicles containing encapsulated ATP can be manufactured on a large scale, and further, that these vesicles can be used for wound care with little systemic reactions. End point: a specific formulation of stable, lyophilized unilamellar lipid vesicles containing ATP with good tissue penetration suitable for wound care and a cGMP process capable of producing these vesicles. 3. The third testable hypothesis is that intracellular ATP delivery will increase wound tissue energy levels, induce coordinated upregulation of growth factors and other healing mechanisms to facilitate healing process. End point: tissue high-energy phosphate contents and their relationship with growth factors and healing speed. None of the 3 topics outlined above has been explored in the past. The success of this project and the expanded use of this new intracellular energy delivery technique will likely have a major impact on medicine. It will not only improve care for chronic wounds, but also improve our ability to treat various ischemic conditions, such as shock, stroke, severe trauma, heart attack, spinal cord injury, cardiopulmonary bypass, organ transplant, acute or chronic lung diseases, and many other conditions involving ischemia. The specific aims of this Phase II proposal are to investigate high-energy phosphate contents in human non-healing chronic wounds, to further improve our direct intracellular energy delivery technique, to use this technique in wound treatment, and to study some of the mechanisms by which intracellular energy supply enhances wound healing. Our Phase I project has improved formulation, encapsulation rate, and particle size of our intracellular ATP delivery preparation, measured high-energy phosphate contents in human chronic wounds, and used the intracellular ATP delivery in animal models. Our intracellular ATP delivery technique caused extremely fast granular tissue growth in rabbit ear wounds. None of the tasks outlined in the current project has been explored in the past. The success of this project and the expanded use of this new intracellular energy delivery technique will likely have a major impact on medicine. It will not only improve care for chronic wounds, but also improve our ability to treat various ischemic conditions, such as shock, stroke, severe trauma, heart attack, spinal cord injury, cardiopulmonary bypass, organ transplant, acute or chronic lung diseases, and many other conditions involving ischemia.