干细胞在组织工程血管构建中的应用

Application of stem cells in construction of tissue-engineered blood vessels

学术背景:组织工程三大要素为种子细胞、支架材料和信息因子。就种子细胞而言,干细胞因具有多种分化潜能成为研究的热点。目的:本文讨论了干细胞在组织工程血管应用中的现状、问题和前景。检索策略:应用计算机检索Pubmed数据库2002-01/2007-03期间相关文章,检索词为"stem cell,blood vessel,tissue engi-neering,differentiation",限定语言种类为英文。并检索万方中文数据库2004/2007年相关文章,检索词为"干细胞,诱导,人工血管"。依照发表论文的权威性及内容相关程度等标准对文章进行初选,共检索到150篇文章,排除较为陈旧的文献,以及相关程度不大的部分,最终选取62篇。文献评价:初步选择引用的62篇文章中,3篇为学术背景介绍,其余59篇大部分涉及近些年干细胞领域研究比较集中的间充质干细胞、造血干细胞和胚胎干细胞,研究的范围涉及细胞诱导分化及其在血管组织工程中的应用。①种子细胞部分:间充质干细胞10篇,造血干细胞9篇,胚胎干细胞7篇,基因修饰5篇。②在诱导分化部分:生长因子6篇,力学因素5篇,细胞外基质9篇,共培养3篇。③组织构建部分5篇。资料综合:已经用于组织工程血管构建的干细胞种类主要有间充质干细胞、造血干细胞、外周血干细胞、胚胎干细胞等。利用干细胞构建组织工程血管的重要手段之一就是在分离、培养得到足够数量的种子细胞后,使其沿着预想的轨迹分化为所需的目的细胞。干细胞的分化主要受其所生长微环境如生长因子、细胞外基质、力学环境、邻近细胞等条件的调控。因此,通过适当控制这些因素单独或协同作用,使其向内皮和平滑肌细胞系分化,对组织工程血管的构建具有巨大的意义。结论:干细胞作为种子材料构建组织工程血管具有光明和广阔未来的研究领域,但在整个技术完全成熟之前还有很多问题需要完善。

BACKGROUND： Tissue engineering comprises seed cells, scaffold material and information factors. Stem cells with multiple-directional differentiation potential have been widely studied. OBJECTIVE： This article aimed to summarize the present status, problems and prospect of stem cell application in tissue-engineered blood bessel. RETRIEVAL STRATEGY： A computer-based online search of Pubmed database was undertaken to identify the relevant articles published from January 2002 to March 2007 in English with the key words of ＂stem cell, blood vessel, tissue engineering, differentiation＂. Meanwhile, with the Chinese articles were retrieved from Wanfang Database between 2004 and 2007, with the key words of ＂stem cells, induction, vascular prosthesis＂. Articles were primarily selected in accordance with authority and relevant degree. A total of 150 articles were collected but some were excluded due to the outdated or less interrelated content. Consequently, 6 articles were selected. LITERATURE EVALUATION： Of the 62 selected articles, 3 were on academic background, and the remaining was on differentiation and application of mesenchymal stem cells, hematopoietic stem cells and embryonic stem cells in vascular tissue engineering. （1）There were 10 articles on mesenchymal stem cells, 9 on hematopoietic stem cells, 7 on embryonic stem cells and 5 on gene modification. （2）There were 6 articles on growth factor, 5 on mechanics factor, 9 on extracellular matrix and 3 on coculture. （3）There were 5 articles on tissue construction. DATA SYNTHESIS： Mesenchymal stem cells, hematopoietic stem cells, peripheral blood stem cells and embryonic stem cells have been used in vascular tissue engineering. Stem cells used in tissue-engineered vessels refer to the differentiation of stem cells into target cells after isolation and culture. Differentiation of stem cells is adjusted by growth microenvironment such as growth factor, extracellular matrix, mechanics environment and surrounding cells. Therefore, the differentiation of stem cells into endothelial cells and smooth muscle cells has a great significance of constructing tissue-engineered vessel by regulation. CONCULSION： Although it needs plenty of work before the entire achievement, using the stem cells as the seed cells to construct the tissue-engineered blood vessel can make a prospective future.