Mechanisms of Prosthetic Arterial Graft Failure

描述（由申请人提供）：这是一项创建生物活性人工动脉移植物的提案，该移植物将基因沉默纳入抗血栓形成和促血管生成表面。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，分子生物学和外科手术，所有这些都以血管移植物为重点。该项目建立在我们长期工作的基础上，我们1）描述了人工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对移植物表面进行生物修饰（重组水蛭素）和内皮细胞生长因子（VEGF）延迟血栓形成和改善内皮化，和4）确定与AIH发展相关的独特基因特征，包括鉴定高度关注的致病性靶。本发明的目的是1）通过使用siRNA在内皮细胞和平滑肌细胞中进行体外功能丧失研究，证实MARCKS、CDH 11和TSP 2参与AIH的发病机制，（二）创建生物活性静电纺丝纳米纤维移植材料，并确定在脉动流和手术室条件下将siRNA有效递送至脉管系统所需的最佳物理性质条件下，以及3）在大鼠模型中进行初步测试后，将移植物原型植入大型犬科动物模型中，并依次确定其递送siRNA、有效诱导基因沉默和积极影响AIH病变发展（包括移植物愈合和通畅）的潜力。这是一项逐步的研究，为基因沉默的有效应用提供了独特且适当广泛的专业知识，以改善人工动脉移植物的结果。该信息还将对更广泛地使用材料来递送用于治疗目的的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.