中文摘要：

目的：观察低密度传代培养对人脂肪基质细胞的形态、增殖能力和表面抗原表达的影响。 方法：实验于2004-05／2006—01在上海交通大学医学院附属第九人民医院整形外科和组织工程研究中心完成。①吸脂术获得脂肪组织，经胶原酶消化分离。（函培养脂肪基质细胞，原代细胞80％融合后分别以5000／cm^2和1000／cm^2的接种密度传代至第3代。③四唑盐比色法和流式细胞法检测比较不同密度传代培养对细胞形态、增殖能力及表面抗原表达的影响。 结果：①低密度传代培养的细胞形态相对均一、体积较小。②四唑盐比色法结果显示低密度传代细胞增殖活力与高密度传代培养组差异无显著性。③流式细胞学检测结果表明，低密度培养组表达CD105，CD166，Stro-1，Flk-1等干细胞相关表面抗原的细胞比例显著高于高密度培养组。 结论：低密度传代培养有利于脂肪基质细胞的体外增殖，并能显著提高细胞群体中干细胞的比例，有可能发展成为一种简便的脂肪干细胞纯化方法。

英文摘要：

AIM：To investigate the change of cell morphology, proliferation ability and expression of cell-surface antigen when human adipose-derived stromal cells （ADSCs） are seeded at low density in repeated passages. METHODS：The experiment was conducted at the Department of Plastic Surgery and Tissue Engineering Center, the Ninth Affiliated Hospital of Shanghai Jiaotong University between May 2004 and January 2006.①Fatty tissues were obtained by liposuction, then digested and isolated by collagenase.②ADSCs were seeded at different densities （5 000 and 1 000 cells/cm^2） and cultured to passage 3 after primary cells completed 80% confluence.③MTY method was used to compare the cell morphology and proliferation ability, and the range-of cell surface epitopes was identified by flow cytometer. RESULTS： ①More small and round cells was found in low density seeding group. ②MTT result demonstrated that the cells which were seeded at low density had the same proliferation ability as those in high density group. By flow cytometer assay, the proportion of cells with stem cell related surface epitopes, such as CD105, CD166, Stro-1 and Flk-1 in low density group was significantly higher than those of high density group. CONCLUSION：The low-density subculture can promote the proliferation of ADSCs, and markedly enhance the proportion of stem cells in ADSCs, thus this method may come to be a convenient way to purify the ADSCs.