骨髓间充质干细胞在骨组织工程中的应用

目的:综述具有向多种细胞分化潜能的骨髓间充质干细胞的生物学特性、分离纯化与培养技术、向骨和软骨定向诱导分化技术、细胞载体支架及其应用于骨组织工程的实验研究。资料来源:应用计算机检索Medline数据库1990-01/2004-12期间的相关文章,检索词“mesenchymalstemcell,tissueengineer”,限定文章语言种类为英文。同时计算机检索中国期刊全文数据库、万方数据库1994-01/2004-12期间的相关文章,检索词″间充质干细胞、组织工程″,限定文章语言种类为中文。资料选择:对资料进行初审,选取间充质干细胞特性、分离培养技术和其应用于组织工程的文献,重复研究选取代表性的、年代相对较近的文献作为纳入标准;然后筛除非骨组织工程的研究和重复研究,对剩余的文献开始查找全文。资料提炼:共收集到78篇关于间充质干细胞应用于组织工程方面的文章,纳入31篇;排除47篇,13篇为重复研究,34篇为非骨组织工程研究。资料综合:间充质干细胞主要存在于骨髓中,能向多种组织细胞分化,在体外可大量扩增。①间充质干细胞的分离纯化和培养目前主要有3种方法:密度梯度离心法、流式细胞仪分离法、贴壁筛选法。也有学者采用单细胞克隆技术获得纯化的间充质干细胞细胞株,但此种方法不便于大量获得种子细胞,目前应用较广泛的是密度梯度离心技术。②间充质干细胞在适宜的培养基中加入诱导剂可向骨、软骨细胞分化,其理想的载体支架应能均匀地搭载并保留细胞,支持血管快速内生,能透X射线利于观察新骨形成,新骨形成后能被吸收和替代以利骨改建,能容许或提高宿主骨的骨传导性桥接,表面与细胞相互作用以保留分化细胞的功能,组织相容性好。③间充质干细胞是理想的基因治疗的靶细胞,它可以转入生长因子和细胞因子基因,经多次分裂后体外仍表达外源蛋白。它应用于骨组织工程的动物试验中已获得了成功。结论:以干细胞工程为代表的现代组织工程学近年来发展迅猛,但间充质干细胞组织工程学尚处于起步阶段。骨髓间充质干细胞具有易于取材、多组织分化潜能、遗传背景稳定、植入体内无排斥反应、高增殖的特性,决定了其将会成为细胞、基因治疗以及组织工程中十分有用的工具。

Bone marrow mesenchymal stem cell in bone tissue engineering

OBJECTIVE: To summarize the biocharacteristics, separation and purification as well as the culture technique of bone marrow mesenchymal stem cell, which has the potentiality of multiple cellular differentiations, locatedinduced differentiation of bone and cartilage, cellular carrying tray and application in bone tissue engineering.DATA SOURCES: Relative articles were retrieved through Medline database according to the key words of "mesenchymal stem cell, tissue engineer" in English between January 1990 and December 2004. Meanwhile,relative articles were also retrieved in Chinese journal full-text database and Wanfang database with the same key words in Chinese between January 1994 and December 2004.STUDY SELECTION: Articles were retrieved first to select those references which were related to the aspects of biology, isolation and culture of mesenchymal stem cell in tissue engineering. Representative and lated references were included; however, researches on non-bone tissue engineering and repetitive studies were excluded. The rest of articles were looked up for their full text.DATA EXTRACTION: There were 78 articles on mesenchymal stem cell in tissue engineering. Among them, 31 papers were included; the otherbut 47 papers including 13 articles of similar contents and 34 studies on nonbone tissue engineering were excluded.DATA SYNTHESIS: Mesenchymal stem cell mainly existed in bone marrow and could differentiated into multiple tissue cells and increase in vitro.① There were three methods for separation, purification and culture of mesenchymal stem cells: density gradient centrifugation, flow cytometry and adherent screening method. Other scholars obtained cell strain of mesenchymal stem cell through single-cell cloning technique, but this way was more difficult to obtain multiple seed cells. At present, density gradient centrifugation was widely used. ② Mesenchymal stem cell could differentiate into bone cells and cartilae cells through adding inductor into eligible culture medium. Ideal scaffolds could carry and retain the vitality of cells, support rapid endogeny of vessels and be benefit for observing new bone formation under X ray. New bone might be absorbed and replaced in bone rebuilding and form or increase conductive bridging of host bone. Functions of differentiated cells could be maintained by the interaction between scaffolds surface and cells, and the histocompatibility was well. ③ Mesenchymal stem cell was an kind of ideal target cells for gene therapy. It could shift growth factor or cytokine and express foreign protein after multiple desintegration in vitro. It was successful in bone tissue engineering.CONCLUSION: Modern tissue engineering which is presented by stem cells develops quickly at present, but tissue engineering of mesenchymal stem cell starts just now. Bone marrow mesenchymal stem cell is characterized by easily materializing, potentiality of multiple tissue differentiation, stable genetic background, non-rejection in implant button and high proliferation. All properties determine that it will be a useful thing in cell and gene therapy as well as tissue engineering.