Multivalent Conjugates of Sonic Hedgehog to Accelerate Diabetic Wound Healing

2010年，超过875，000名美国糖尿病患者被诊断患有下肢溃疡。这些伤口闭合失败导致每年超过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，并减少清创和临床观察这些缓慢愈合的伤口所需的昂贵的连续努力。我们的专利技术是一种化学拴系过程，使我们能够控制在受体附近传递的生长因子的化合价。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，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缀合至大的大分子还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血管形成。用于Shh治疗的Valitor方法将能够增强体内Shh生物活性，并且将我们的治疗剂递送到伤口床中可以以低治疗成本显著改善患者的长期结果。我们在I期的总体目标是开发mvShh缀合物，其在协调皮肤伤口愈合的细胞类型中引起增强的Shh通路活化和下游血管生成基因表达。在具体目标1中，我们将使用从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）中收获的真皮成纤维细胞，在体外鉴定产生最大Shh通路活化的mvShh制剂。然后，我们将确定Shh化合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。在具体目标2中，我们将证明mvShh缀合物将使用全层切除伤口模型在db/db小鼠中启动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治疗方法的进一步临床前开发提供有价值的概念验证数据，我们计划在该项目的第二阶段进行。 公共卫生相关性：2010年，超过875，000名美国糖尿病患者被诊断患有慢性下肢溃疡，这些患者每年产生超过300亿美元的相关医疗保健费用。Valitor公司正在开发一种先进的治疗方法，以加速糖尿病伤口的愈合，通过促进新血管形成和改善伤口床的血液供应来抵消治疗的高成本。我们第一阶段项目的总体目标是将我们的治疗参数与血管形成的细胞机制联系起来，并证明我们的技术作为临床治疗的概念验证。

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.