Blood Outgrowth Endothelial Cell Seeding of Heart Valve Leaflets

描述（由申请人提供）：拟定研究将研究一种通过使用三叶聚氨酯人工瓣膜置换治疗心脏瓣膜疾病的新方法，该人工瓣膜使用血液生长内皮细胞（BOEC）进行内皮接种。我们将研究Abiomed（Danvers，MA）生产的AbioCor聚氨酯瓣膜（ABV）。ABV已用于7,000多名人类受试者。假设BOEC接种的ABV可有效抵抗聚氨酯心脏瓣膜衰竭的主要原因，包括血栓形成、钙化和瓣叶表面的氧化降解。目的1.合成并表征一种新型的双组分光活化复合物，用于胆固醇表面修饰聚氨酯心脏瓣膜小叶，以假设在高流动和高剪切下增加BOEC粘附。我们的合成方法将使用两步法，使用：1）可光活化的聚烯丙基胺-苯并酮化合物，称为PBPC，以活化聚氨酯心脏瓣膜小叶的表面，用于随后连接到光连接的PBPC，2）胆固醇衍生的聚烯丙基胺，用硫醇反应性基团和离子基团进行生物化学改性-该复合物的第二组分称为CPB。这些研究的目标是创建一组候选PBPC-CPB制剂，用于目标2和3的研究。目标2.用PBPC-CPB改性的聚氨酯表面促进BOEC粘附的体外研究。这些研究将评估粘附机制、BOEC表型稳定性、内皮功能和各种候选CPB的激活。然后，我们将研究用领先的CPB化合物修饰的ABV和接种有二尖瓣流动模拟的BOEC。总之，这些研究将用于理解粘附机制并指导候选PBPC-CPB中的制剂变更，这将导致下文所述目标3中的最佳体内细胞粘附。目标3。BOEC接种的体内研究（使用绵羊），将研究最佳PBPC-CPB制剂。将研究两种体内模型系统：1）主动脉按钮模型植入物，其将在2周研究中评估BOEC粘附、表型稳定性和抗血栓性。还将研究外植体的细胞覆盖范围、内皮表型稳定性、非内皮细胞类型的存在、内皮活化以及血小板和纤维蛋白血栓沉积。2)使用PBPC-CPB改性的ABV表面和BOEC接种和未改性对照对绵羊进行二尖瓣置换术，为期150天，目的是评估BOEC粘附和表型稳定性以及预防血栓、钙化和氧化降解的疗效。公共卫生相关性：项目叙述心脏瓣膜疾病影响数百万人，只能通过心脏手术治疗。此外，目前的人工心脏瓣膜经常由于血栓形成和主要材料失效而失效。本提案将通过研究植入自体血液生长内皮细胞的三叶聚氨酯瓣膜，研究心脏瓣膜置换术的新方法。

DESCRIPTION (provided by applicant): The proposed research will study a novel approach for treating heart valve disease via the use of heart valve replacements with trileaflet polyurethane prostheses that are endothelial seeded using blood outgrowth endothelial cells (BOEC). We will investigate the AbioCor polyurethane valve (ABV), manufactured by Abiomed (Danvers, MA). The ABV has been used in more than 7,000 human subjects. BOEC seeded ABV are hypothesized to be efficacious for resisting the principal causes of polyurethane heart valve failure, which include thrombosis, calcification and oxidative degradation of leaflet surfaces. Aim 1.Synthesize and characterize a novel two component photoactivated complex for surface modifying polyurethane heart valve leaflets with cholesterol to hypothetically increase BOEC adhesion under high flow and high shear. Our synthetic methods will use a two step approach using: 1) A photo- activatable polyallylamine-benzophone compound, referred to as PBPC, to activate the surface of polyurethane heart valve leaflets for the subsequent attachment to the photo-linked PBPC of, 2) a cholesterol-derivatized polyallylamine, biochemically modified with thiol-reactive groups and ionogenic groups--this 2nd component of the complex is referred to as CPB. The goal of these studies will be to create a candidate set of PBPC-CPB formulations for investigation in Aims 2&3. Aim 2. In vitro investigations of polyurethane surfaces modified with PBPC-CPB to promote BOEC adhesion. These studies will assess adhesion mechanisms, BOEC phenotype stability, endothelial function and activation with various candidate CPB. We will then study ABV modified with lead CPB compounds and BOEC seeded with mitral valve flow simulations. Taken together, these studies will be used to both understand adhesion mechanisms and guide formulation changes in candidate PBPC-CPBs that will result in optimal in vivo cell adhesion in Aim 3 described below. Aim 3. In vivo studies (using sheep) of BOEC seeding that will investigate optimal PBPC-CPB formulations. Two in vivo model systems will be studied: 1) An aortic button model implant that will assess BOEC adhesion, phenotype stability and thrombo-resistance in 2 week studies. Explants will also be studied for extent of cell coverage, endothelial phenotype stability, the presence of nonendothelial cell types, endothelial activation, and platelet and fibrin thrombus depositon. 2) Mitral valve replacements in sheep with ABV surface modified with PBPC-CPB and BOEC seeded and nonmodified controls will be carried out for 150 days with the goal of assessing both BOEC adhesion and phenotype stability, and therapeutic efficacy for preventing thrombus, calcification and oxidative degradation. PUBLIC HEALTH RELEVANCE: Project Narrative Heart valve disease affects millions and is only treatable by cardiac surgery. In addition current artificial heart valves fail frequently due to thrombosis and primary material failure. This proposal will investigate a novel approach for a heart valve replacement by studying a trileaflet polyurethane valve that is seeded with autologous blood outgrowth endothelial cells.