VEGF165/OPG共价修饰去细胞瓣重构介入心脏瓣膜的抗钙化机制研究

Heart valve disease remains a worldwide problem, valve replacement is still the most effective treatment methods. For its good hemodynamic characteristics, no life anticoagulation etc , clinically bioprosthetic valve is more and more broadly applied. At present, the calcification of biological valve implanted in bodies is still international problem. Intercurrent valve and living tissue engineering heart valve are the main trend of bioprosthesis. Our initial study found that the PEG-crosslinking of decellularized valve, not only could improve the mechanical properties of decellularized valve, but also could combine covalently VEGF, so as to promote endothelialization of decellularized valve. In this study, with the help of PEG, VEGF and OPG will be combined covalently onto decellularized valve by Michael addition reaction to construct anti-calcific scaffold materials, which will be combined with memory alloy mesh scaffolds to construct intercurrent valve resisted calcification，and then the intercurrent valve will be transplanted into the aortic valve position of goat by catheter. The purpose of this study is to investigate the optimum conditions and dose proportion of covalent binding between VEGF、OPG and decellularized valve, the interior mechanism between anti-calcification with endothelialization of decellularized valve in vitro and in vivo promoted by VEGF , and the anti-calcification mechanism of OPG, which may provide an idea for future construction of tissue engineering heart valve.

心脏瓣膜病是一个世界性问题,瓣膜置换术仍是目前最有效的治疗方法。生物瓣膜因其良好血流动力学特性、无需终身抗凝等优点,在临床越来越得到广泛应用。目前生物瓣植入体内后出现的钙化,仍然是国际性的难题。介入瓣膜和具有活性的组织工程瓣膜是生物瓣研究的主要发展趋势。我们前期研究发现：PEG交联去细胞瓣，不仅可改善去细胞瓣的力学性能，而且可以共价结合VEGF，从而促进去细胞瓣的内皮化。本课题拟通过迈克尔加成反应，借助PEG将VEGF和外源性抗钙化因子OPG共价结合到去细胞瓣上，构建防钙化瓣膜支架材料；并联合记忆合金网状支架构建带支架可植入防钙化介入心脏瓣膜，经导管将该瓣膜移植到山羊的主动脉瓣位置，旨在探讨VEGF和OPG与去细胞瓣共价结合的最佳反应条件和剂量比例，VEGF促进去细胞瓣体外和体内原位内皮化与防钙化的内在机制，以及OPG抗去细胞瓣钙化的机制，为进一步构建组织工程心脏瓣膜提供新的思路。

心脏瓣膜病是一个世界性问题,瓣膜置换术仍是目前最有效的治疗方法。生物瓣膜因其良好血流动力学特性、无需终身抗凝等优点,在临床越来越得到广泛应用。目前生物瓣植入体内后出现的钙化,仍然是国际性的难题。本研究首次应用无毒的非离子表面活性剂MPEG-PCL作为去细胞试剂，对猪主动脉瓣进行去细胞处理，成功制备具有良好生物学性能和力学性能的主动脉瓣支架仿生材料，并用PEG修饰去细胞瓣膜，结果显示经PEG交联的去细胞瓣，胶原纤维发生交联，使瓣膜的结构更加致密，再经VEGF和OPG共价修饰，复合瓣膜的力学性能和生物学性能均得到一定的改善。本实验建立了一个介入瓣膜实验研究的动物模型和方法，构建一种具有独立知识产权的新型仿生微创抗钙化心脏瓣膜，并且体外性能检测；并借鉴TAVI（Transcatheter aortic valve replacement，经导管主动脉瓣植入术）技术，通过微创动物模型进行体内实验，探讨新型抗钙化心脏瓣膜体内抗钙化的机制，为进一步构建组织工程心脏瓣膜提供新思路。