中文摘要：

人胎儿骨髓间充质干细胞（BMMSCs）的群体倍增次数（70～80次）是成体BMMSCs（30～40次）的2倍，分化能力优于成体干细胞。研究采取纵向剪开骨髓腔涮洗细胞法和全骨髓培养法分离2～3月龄流产胎儿BMMSCs，四甲基偶氮唑盐比色法（MTT法）筛选基础培养液和血清浓度并制作生长曲线，流式细胞仪和免疫组织化学法鉴定细胞抗原标志，并通过核型分析和成瘤实验评估细胞的安全性。结果表明，沿长轴剪开骨髓腔涮洗细胞法是获得2～3月龄人流产胎儿四肢长骨骨髓的实用方法。在实验范围内α-MEM（minimum essential medium alpha medium）＋20％FCS（fetal cattle serum）是体外培养2～3月龄流产胎儿BMMSCs的最佳体系。分离的第3代BMMSCs除表达成体BMMSCs表面抗原标志外还表达Oct4、SSEA3和SSEA4，第6、12和24代细胞在对数增长期的群体倍增时间分别为34、36和40h，且均为二倍体核型、不成瘤。这证明2～3月龄人流产胎儿BMMSCs可以成为人类组织工程和再生医学研究理想的种子细胞。

英文摘要：

The population doubling number （70～80 times） of human fetal bone marrow mesenchymal stem cells （BMMSCs） is about two times more than that （30～40 times） of the adult BMMSCs, and their differentiation capacity is superior to that of their adult counterparts. In this study, BMMSCs were isolated from 2- to 3-month-old human abortuses by scissoring their long bones lengthwise, followed by rinsing and culturing whole marrow cells. Basic medium and serum concentration for BMMSCs culture were optimized and growth curves made, both with MTT（3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetmzoliumromide） reduction assay. Isolated cells were identified with flow-cytometry and immunocytochemistry for their antigen markers. The biosafety of isolated cells was evaluated by karyotype analysis and tumor forming experiment. The results indicated that lengthwise scissoring of fetal long bones and rinsing of their marrow cells was practical and useful to obtain the BMMSCs from human abortuses at the age of 2～3 months. In this experiment, α-MEM（minimum essential medium alpha medium） ＋20% FCS（fetal cattle serum） was the best system for the BMMSCs in vitro. The third passage BMMSCs expressed Oct4, SSEA3 and SSEA4 beside the surface markers of their adult counterparts. The population doubling time of the BMMSCs of passage 6, 12 and 24 were 34,36 and 40 h, respectively. The cells in all the passages showed diploid karyotype and formed no tumor in the nude mice. The BMMSCs of human abortuses at the age of 2～3 months were proved to be biologically safe and ideal seed cells for researches on human tissue engineering and regeneration medicine.