INTRACELLULAR ENERGY DELIVERY AND DIABETIC WOUNDS

描述（由申请人提供）：我们项目的长期目标是开发一种安全有效的技术来对抗各种组织缺血性损伤。这项建议的具体目的是利用我们新开发的专有细胞内能量输送技术来促进糖尿病伤口的愈合。在1700万患有糖尿病的美国人中，大约有250万到450万人在他们的一生中会患上慢性伤口。糖尿病足问题的总成本，包括生产力损失，每年可能高达200亿美元。尽管开发了数千种用于治疗伤口的敷料产品，但没有一种显示出一致的效果。我们提出了一种治疗慢性伤口的新方法。我们的中心假设是伤口组织缺氧导致三磷酸腺苷（adenosine triphosphate， ATP）的耗竭，这是慢性伤口无法愈合的根本原因，而细胞内ATP的直接递送将改善伤口组织的微环境，促进愈合过程。直接能量供应用于伤口治疗以前从未尝试过，能量供应增加与伤口愈合过程之间的关系是完全未知的。在Pi的NIH资助期间，题为“增强糖酵解用于低温心脏保存”，已经开发了一种直接在细胞内递送ATP的新技术，其中使用特殊载体来封装ATP。这种载体的组成与细胞膜相似。当载体与细胞膜相遇时，它与细胞膜融合并将内容物输送到细胞质中。初步结果表明，这种新的能量传递技术对缺血细胞和组织具有明显的保护作用。该技术在正常和缺血性伤口上显示出非常有前景的效果。已经申请了3项美国专利和超过12项国际专利，并向美国国立卫生研究院报告了这项创新。我们的初步结果还表明，人类慢性伤口的高能磷酸磷含量严重减少，动物伤口的atp囊泡处理增加了组织高能含量。本文将检验五种假设：(1)慢性糖尿病创面中高能磷酸盐含量降低；2)使用微创手术技术创建的缺血性伤口模型对糖尿病动物可耐受；3)细胞内ATP递送会增加伤口组织能量水平，促进愈合；(4)通过向伤口组织提供能量，通过协调上调生长因子和其他愈合机制来促进愈合；(5)直接的细胞内能量传递将通过改善组织灌注来促进伤口愈合。这些问题在过去没有被探讨过，但是我们的初步结果为这个项目的成功奠定了基础。细胞内直接能量传递的使用范围的扩大可能会对医学产生重大影响。它不仅可以改善慢性伤口护理，还可以帮助我们治疗各种缺血性疾病，如严重创伤，休克，中风，心脏病发作，脊髓损伤，体外循环，器官移植，以及许多其他急慢性缺血性疾病。

DESCRIPTION (provided by applicant): The long-term goal of our program is to develop a safe and effective technique to combat various tissue ischemic damages. The specific aim of this proposal is to use our newly developed proprietary intracellular energy delivery technique to promote healing of diabetic wounds. Of the 17 million Americans with diabetes, approximately 2.5 to 4.5 million will develop a chronic wound in their lifetime. The overall cost of diabetic foot problems, including loss of productivity, could be as high as $20 billion per year. Despite thousands of dressing products developed to treat wounds, none have shown consistent effect. We propose a new approach for chronic wounds. Our central hypoth- esis is that wound tissue hypoxia results in depletion of adenosine triphosphate (ATP), which is the fundamental cause of non-healing chronic wounds, and a direct intracellular ATP delivery will improve microenvironment of wound tissue and facilitate healing process. Direct energy supply for wound treatment has never been attempted before, and the relationship between increased energy supply and wound healing process is entirely unknown. During the tenure of the Pi's NIH grant entitled "Enhanced glycolysis for hypothermic heart preservation", a new technique for direct intracellular delivery of ATP has been developed in which a special carrier is used to encapsulate ATP. The composition of this carrier is similar to the cell membrane. When the carrier meets with the cell membrane, it fuses with it and delivers the contents into the cytosol. Preliminary results indicate that this new energy delivery technique can provide significant protection to ischemic cells and tissues. The technique has shown very promising effects on normal and ischemic wounds. Three US patents and more than 12 international patents have been filed and the innovation has also been reported to the NIH. Our preliminary results also indicated that high-energy phos- phate contents were severely depleted in human chronic wounds, and treatment with ATP-vesicles in animal wounds increased tissue high-energy contents. Five hypotheses will be tested: (1) high-energy phosphate contents are decreased in chronic diabetic wounds; 2) an ischemic wound model created using a minimally invasive surgical technique can be tolerable to diabetic animals; 3) intracellular ATP delivery will increase wound tissue energy levels to facilitate healing; (4) by providing energy to wound tissue, improved healing is achieved through coordinated upregulation of growth factors and other healing mechanisms; and (5) direct intracellular energy delivery will enhance wound healing by improved tissue perfusion. These issues have not been explored in the past, but our preliminary results have established the basis for the success of this project. The expansion of usage of the direct intracellular energy delivery is likely to have a major impact on medicine. It will not only improve chronic wound care, but also help our treatment to various ischemic conditions, such as severe trauma, shock, stroke, heart attack, spinal cord injury, cardiopulmonary bypass, organ transplant, and many other acute and chronic ischemic diseases.