Partial-thickness wound healing via topical ATP delivery

描述（由申请人提供）：我们项目的长期目标是开发安全有效的技术来对抗缺血引起的组织损伤。本提案的具体目的是研究人类不愈合慢性伤口中的高能磷酸盐含量，进一步改进我们的直接细胞内能量输送技术，将该技术用于伤口治疗，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，高能量磷酸盐含量的消耗是不愈合的慢性伤口的根本原因;并且ATP直接细胞内递送到伤口将改善微环境并显著增强愈合过程。我们的I期研究结果还发现：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降低; 2）在兔耳模型中，使用VitaSolTM的细胞内ATP输送显著增加了伤口组织高能磷酸盐含量; 3）细胞内ATP输送导致颗粒组织极快生长。使用微创外科手术，我们还开发了一种新的兔缺血性伤口模型，该模型首次成功用于糖尿病动物。第一阶段研究的结果证明了我们的基本概念。本II期研究将追求三个目标：1.第一个可检验的假设是伤口组织缺氧导致高能磷酸盐可用性降低，并且这种降低是慢性伤口不愈合的主要原因。终点：人体各种慢性伤口中高能磷酸盐含量。2.待检验的第二个假设是，可以大规模制造含有包封的ATP的单层脂质囊泡，并且进一步地，这些囊泡可以用于伤口护理而几乎没有全身反应。终点：含有ATP的稳定的、冻干的单层脂质囊泡的特定制剂，其具有良好的组织渗透性，适用于伤口护理，以及能够产生这些囊泡的cGMP方法。3.第三个可检验的假设是细胞内ATP递送将增加伤口组织能量水平，诱导生长因子和其他愈合机制的协调上调以促进愈合过程。研究终点：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3个主题过去都没有探讨过。该项目的成功以及这种新的细胞内能量输送技术的广泛使用可能会对医学产生重大影响。它不仅将改善对慢性伤口的护理，而且还将提高我们治疗各种缺血性疾病的能力，例如休克、中风、严重创伤、心脏病发作、脊髓损伤、心肺转流术、器官移植、急性或慢性肺部疾病以及涉及缺血的许多其他疾病。本II期提案的具体目的是研究人类不愈合慢性伤口中的高能磷酸盐含量，进一步改进我们的直接细胞内能量输送技术，将该技术用于伤口治疗，并研究细胞内能量供应促进伤口愈合的一些机制。我们的I期项目改进了我们的细胞内ATP递送制剂的配方、包封率和粒径，测量了人类慢性伤口中的高能磷酸盐含量，并在动物模型中使用了细胞内ATP递送。我们的细胞内ATP递送技术在兔耳伤口中引起了极快的颗粒组织生长。本项目中概述的任务过去都没有探讨过。该项目的成功以及这种新的细胞内能量输送技术的广泛使用可能会对医学产生重大影响。它不仅将改善对慢性伤口的护理，而且还将提高我们治疗各种缺血性疾病的能力，例如休克、中风、严重创伤、心脏病发作、脊髓损伤、心肺转流术、器官移植、急性或慢性肺部疾病以及涉及缺血的许多其他疾病。

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.