Multivalent Conjugates for Enhanced Bioactivity of Growth Factor Based Therapies

用于增强生长因子疗法的生物活性的多价缀合物

• 批准号: 8544176
• 负责人: KEVIN Edward HEALY
• 金额: $ 16.66万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8544176
• 关键词: American; Amputation; Angiogenic Factor; Animal Model; Area; Back; Beds; Biological; Biopolymers; Blood Vessels; Cellular Infiltration; Chemistry; Chronic; Clinical; Complications of Diabetes Mellitus; Control Groups; Coronary; Dental; Dermal; Diabetes Mellitus; Diabetic Angiopathies; Diabetic ulcer; Diabetic wound; Diagnosis; Digestion; Disease; Drug Formulations; Drug or chemical Tissue Distribution; Endothelial Cells; Environment; Erinaceidae; Etiology; Exhibits; Fibroblasts; Gene Expression; Genes; Goals; Growth Factor; Harvest; Healed; Health Care Costs; Hyaluronic Acid; Immunohistochemistry; Impaired wound healing; In Vitro; Infection; Infiltration; Injury; Insulin-Like Growth Factor I; Investigation; Ischemia; Leg Ulcer; Limb structure; Lower Extremity; Measures; Metabolic Clearance Rate; Modeling; Molecular; Muscle; Natural regeneration; Necrosis; Orthopedics; Pathway interactions; Peptide Hydrolases; Platelet-Derived Growth Factor; Polymers; Proteins; Recombinant Growth Factor; Saline; Signal Transduction; Site; Sonic Hedgehog Pathway; Technology; Testing; Therapeutic; Thick; Time; Tissues; Transcription Coactivator; Translations; Vascular blood supply; Vascularization; Vertebral column; Wound Healing; angiogenesis; base; db/db mouse; design; diabetic; diabetic wound healing; disease phenotype; healing; immune function; improved; in vivo; macromolecule; neovascularization; novel therapeutic intervention; prevent; smoothened signaling pathway; tissue regeneration; treatment strategy; wound; wound vascularization

DESCRIPTION (provided by applicant): 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. One common feature to these wounds is inadequate vascularization of the wound bed, leading to ischemia, infection, and necrosis. In addition to diabetic ulcers, limited vascularization during regeneration of coronary, orthopaedic, dental and muscle tissues are frequent diabetic complications. Several growth factors, including Sonic hedgehog (Shh), can enhance wound healing by promoting neovascularization in the wound, but they are rapidly cleared from the wound environment and subject to proteolytic digestion. Thus, the translation of growth factors as clinical therapies has been limited by their short duration of site-specific bioactivity in vivo. We have developed multivalent growth factor conjugates that are designed to enhance the bioactivity and tissue-level stability of growth factors to facilitate their clinical translation as biological therapeutics. Using this approach, w have conjugated Shh 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. Our overall hypothesis is that multivalent conjugates of Shh (mvShh) will enhance and sustain Shh-induced gene expression that promotes neovascularization during diabetic wound healing. In Specific Aim 1, we will identify the mvShh formulations that yield maximal 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. In Specific Aim 2 we will correlate the bioactivity of mvShh conjugates to their ability to accelerate healing of full-thickness excisional wounds in db/db mice. Finally, in Specific Aim 3 we will use the same db/db wound healing model to investigate how multivalent presentation of Shh can enhance Shh-induced expression of angiogenic genes and blood vessel formation in vivo. By testing our hypothesis, we will evaluate mvShh conjugates as a treatment for diabetic ulcers. The general mechanism of multivalent conjugation of Shh in angiogenic signaling may also be extended to a variety of other microvascular disorders. Likewise, this study will build a rationale for multivalent conjugation as an enabling strategy for protein-based therapies that require local delivery and sustained bioactivity.

描述（由申请人提供）：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。这些伤口的一个共同特征是伤口床的血管形成不足，导致缺血、感染和坏死。除了糖尿病溃疡，冠状动脉、骨科、牙齿和肌肉组织再生期间的血管化受限也是常见的糖尿病并发症。包括Sonic hedgehog（Shh）在内的几种生长因子可以通过促进伤口中的新血管形成来增强伤口愈合，但它们会从伤口环境中迅速清除并经受蛋白水解消化。因此，作为临床治疗的生长因子的翻译受到其体内位点特异性生物活性持续时间短的限制。我们已经开发了多价生长因子缀合物，其设计用于增强生长因子的生物活性和组织水平稳定性，以促进其作为生物治疗剂的临床转化。使用这种方法，我们已经将Shh缀合到透明质酸（HyA）的线性链上，并且通过改变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。我们的总体假设是， Shh（mvShh）将增强和维持Shh诱导的基因表达，促进糖尿病伤口愈合期间的新血管形成。在特定目标1中，我们将使用从db/db小鼠（一种显示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鉴定在体外产生最大途径活化的mvShh制剂。在具体目标2中，我们将mvShh缀合物的生物活性与其加速db/db小鼠中全层切除伤口愈合的能力相关联。最后，在具体目标3中，我们将使用相同的db/db伤口愈合模型来研究Shh的多价呈递如何在体内增强Shh诱导的血管生成基因表达和血管形成。通过测试我们的假设，我们将评估mvShh缀合物作为糖尿病溃疡的治疗。Shh在血管生成信号传导中多价缀合的一般机制也可以扩展到多种其他微血管疾病。同样，本研究将建立多价缀合的理论基础，作为需要局部递送和持续生物活性的基于蛋白质的疗法的使能策略。