组织工程组织血管化研究新进展

Advances in vascularization of tissue-engineered graft

组织工程的血管化问题是制约组织工程产品的关键问题之一。根据血管发生中内皮细胞的来源不同,将血管发生分血管生成和血管再生两种形式,两种血管形成的方式都是一个动态、复杂的生理过程,通过生长因子和粘附物质来调节。对组织工程组织的血管化研究模型有体外和体内两种。体外实验可以检测支架与内皮细胞的粘附、增殖及迁移、材料的细胞毒、血管化效应和各种生长因子的调节作用,体内最简单实用的模型是用鸡胚茸毛尿囊膜模型,更高等的实验模型是在完整的动物体。组织工程组织血管化的策略有对支架材料的表面结构进行修饰、在材料内复合缓释的生长因子、内皮细胞与其它种子细胞联合培养、体内血管网包裹、血管束植入、血管模板以及体外在人造组织内构造微血管等,但目前的方法或多或少地存在一些问题,相信随着对血管化的机制和分子基础的了解的不断深入,以及各种技术手段的不断发展、完善,最终会找到比较理想的血管化方法。

Vascularization is one of the major c hallenges in tissue engineering gra ft.Vascular plexus falls into two modes which are different in recourse of endotheliocyte:vascul ogenesis and angiogenesis.Both mod es are a dynamic and complicated physiological process.Various kinds of growth factor and adhesion molecule modula te the process.Both in vitro and in vivo methods are used in vascularization research.In vitro methods are used to e-valuate biomaterials for endothelial cell attachment,cytotoxicity,g rowth,angiogenesis and its effects on gene reg-ulation.Chorioallantoic membrane(CAM)is one of the simplest and effective models in vivo.Animals are used as more advanced models.The strategie s of vascularization of tissue engin eering include:modification of the surface of the biomaterials,addition of slow-release growth factor to scaffold,e ndotheliocyte cocultured with other seed cells,wrapping by vascular net,implantin g blood vessel bundles into the graft,seeding biomaterial implants with vascular remnants as vascular template,and c reating perfused microvessels in vitro.None of these approaches,however,is satisfactory at present.We believe that an ideal method will be finally f ound for vascularization in tissue e ngineering with advancement of research on mech anism of vascularization and progre ss in techniques.[