Mechanisms of Prosthetic Arterial Graft Failure

描述(由申请人提供)：这是一项建议，创造一种生物活性的人造动脉移植物，将基因沉默整合到抗血栓和促进血管生成的表面。该研究团队的凝聚力和专业知识的广度是独一无二的，包括纺织品、聚合物、细胞生物学、分子生物学和外科，所有这些都以血管移植为既定重点。这个项目建立在我们长期工作的基础上，我们1)确定了假体移植物下游吻合口新生内膜增生(AIH)病变的特征，2)确定了血流-表面相互作用在AIH发病机制中的作用，3)通过加入抗血栓药物(RHirudin)和内皮细胞生长因子(VEGF)对移植物表面进行生物修饰，以延迟血栓形成和促进内皮化，4)确定了与AIH发展相关的独特基因特征，包括确定了备受瞩目的致病靶点。目前建议的目标是1)通过使用siRNA对内皮和平滑肌细胞进行体外功能丧失研究，验证Marcks、CDH11和TSP2在AIH发病机制中的作用；2)创建一种生物活性的电纺纳米纤维移植材料，并确定它在脉动流和手术室条件下有效地将siRNA输送到血管系统所需的最佳物理性质；3)在大鼠模型中进行初步测试后，将移植模型植入大型犬动物模型，并依次确定其传递siRNA的潜力、有效地诱导基因沉默，并对AIH损伤的发展，包括移植物愈合和通畅产生积极影响。这是一项循序渐进的研究，在有效应用基因沉默来改善人造动脉移植物的结果方面，带来了独特和适当广泛的专业知识。这些信息还将对更多地使用材料来传递用于治疗目的的siRNA感兴趣。

DESCRIPTION (provided by applicant): This is a proposal to create a biologically active prosthetic arterial graft incorporating gene silencing to an antithrombotic and pro-angiogenic surface. The research team is unique in its cohesiveness and breadth of expertise including textiles, polymers, cell biology, molecular biology, and surgery, all with an established focus on vascular grafts. This project builds on our long-standing work where we have 1) characterized the lesion of anastomotic neointimal hyperplasia (AIH) downstream of the prosthetic graft, 2) established the role of blood flow-surface interaction in AIH pathogenesis, 3) applied biologic modification to the graft surface by incorporating antithrombotic (rHirudin) and endothelial cell growth factor (VEGF) to delay thrombus formation and improve endothelialization, and 4) determined the unique gene signature associated with AIH development, including identification of high profile pathogenic targets. The goals of the current proposal are to 1) Validate the involvement of MARCKS, CDH11, and TSP2 in the pathogenesis of AIH, by means of in vitro loss-of-function studies in endothelial and smooth muscle cells using siRNA, 2) Create a bioactive electrospun nanofibrous graft material and determine optimal physical properties that it requires for effective siRNA delivery to the vasculature under pulsatile flow and operating room conditions and, 3) implant the graft prototype in a large canine animal model, after preliminary testing in a rat model, and determine sequentially its potential to deliver siRNA, effectively induce gene silencing and positively impact the development of AIH lesions, including graft healing and patency. This is a stepwise study bringing to bear a unique and appropriately broad range of expertise on the effective application of gene silencing to improve the outcome of prosthetic arterial grafts. The information will also be of interest in the larger use of materials to deliver siRNA for therapeutic purposes.