Multivalent Conjugates of Sonic Hedgehog to Accelerate Diabetic Wound Healing

2010年，超过87.5万美国糖尿病患者被诊断为下肢溃疡。这些伤口未能愈合导致每年超过73,500例下肢截肢。Valitor公司正在开发蛋白质聚合物疗法，以克服糖尿病伤口愈合的微血管后果。我们设计了我们的治疗方法，以补充糖尿病溃疡管理的标准实践，并减少了对这些缓慢愈合的伤口进行清创和临床观察所需的昂贵的一系列努力。我们的专利技术是一种化学捆绑过程，使我们能够控制在受体附近传递的生长因子的价。利用这项技术，我们将一种重要的血管生成因子Sonic hedgehog （Shh）与透明质酸（HyA）的线性链结合，并通过改变Shh: HyA的比例，我们可以调节其激活Shh通路的能力。将Shh偶联到一个大分子上也可以防止其被蛋白水解酶失活，并增强其在靶组织中的分子稳定性。我们将开发这些多价Shh （mvShh）缀合物，作为加速糖尿病下肢溃疡伤口愈合的治疗方法，因为Shh先前已被证明可以刺激新生血管。Valitor治疗Shh的方法将增强Shh在体内的生物活性，并且将我们的治疗方法输送到伤口床上可以以较低的治疗成本显著改善患者的长期预后。我们在I期的总体目标是开发mvShh偶联物，在协调皮肤伤口愈合的细胞类型中引发增强的Shh通路激活和下游血管生成基因表达。在Specific Aim 1中，我们将利用从db/db小鼠（一种表现出伤口愈合受损和血管生成基因表达减少的糖尿病模型动物）身上获得的真皮成纤维细胞，在体外鉴定能产生最大Shh通路激活的mvShh制剂。然后，我们将确定Shh价对体外微血管内皮细胞增殖和迁移的影响，因为这些是血管生成所需的基本机制。在Specific Aim 2中，我们将在使用全层切除伤口模型的db/db小鼠中证明mvShh偶联物将启动Shh信号传导和下游血管生成基因表达的原理证明。我们的研究结果将为我们的疗法的进一步临床前开发提供有价值的概念验证数据，我们计划在这个项目的第二期进行。

DESCRIPTION: In 2010, more than 875,000 Americans with diabetes were diagnosed with a lower extremity ulcer. Failed closure of these wounds results in more than 73,500 lower extremity amputations annually. Valitor, Inc. is developing protein-polymer therapeutics to overcome the microvascular consequences of diabetic wound healing. We designed our therapy to complement the standard practice of diabetic ulcer management and to reduce the costly serial effort required for debridement and clinical observation of these slowly healing wounds. Our patented technology is a chemical tethering process that enables us control the valency of growth factors that are delivered within the vicinity of a receptor. With this technology, we have conjugated Sonic hedgehog (Shh), an important angiogenic factor, to linear chains of hyaluronic acid (HyA), and by varying the ratio of Shh: HyA, we can modulate its ability to activate the Shh pathway. Conjugating Shh to a large macromolecule may also prevent its deactivation by proteolytic enzymes and enhance its molecular stability in the target tissues. We will develop these multivalent Shh (mvShh) conjugates as a treatment to accelerate wound healing in diabetic lower extremity ulcers, as Shh has previously been shown to stimulate neovascularization. The Valitor approach to Shh therapy will enable enhanced Shh bioactivity in vivo, and delivery of our therapeutic into the wound bed could provide a significant improvement in the patient's long-term outcome at a low treatment cost. Our overall goal during Phase I is to develop mvShh conjugates that elicit enhanced Shh pathway activation and downstream angiogenic gene expression in the cell types that coordinate cutaneous wound healing. In Specific Aim 1, we will identify the mvShh formulations that yield maximal Shh pathway activation in vitro using dermal fibroblasts harvested from db/db mice, a diabetic model animal that exhibits impaired wound healing and diminished angiogenic gene expression. We will then determine the effect of Shh valency on microvascular endothelial cell proliferation and migration in vitro, as these are essential mechanisms required for angiogenesis. In Specific Aim 2, we will demonstrate proof-of-principle that the mvShh conjugates will initiate Shh signaling and downstream angiogenic gene expression in db/db mice using a full-thickness excisional wound model. Our findings will provide valuable proof-of-concept data for further pre-clinical development of our therapeutic, which we have planned for Phase II of this project. PUBLIC HEALTH RELEVANCE: Relevance In 2010, more than 875,000 Americans with diabetes were diagnosed with a chronic lower extremity ulcer, and these patients generate over $30 billion per year in related health care costs. Valitor, Inc. is developing an advanced therapeutic to accelerate healing in diabetic wounds, offsetting the high cost of treatment by encouraging neovascularization and improving blood supply in the wound bed. The overall goal of our Phase I project is to relate the treatment parameters of our therapeutic to the cellular mechanism of blood vessel formation and demonstrate proof-of-concept for our technology as a clinical therapy.