壳聚糖-明胶-碱性成纤维细胞生长因子三维大孔支架对骨髓间充质干细胞增殖的影响

背景:干细胞的分化潜能与培养条件有密切关系,改变支架材料的表面特性,三维结构,增加生长因子均可实现对干细胞增殖分化的控制.目的:制备适合骨髓间充质干细胞附着生长的、具有最佳孔隙率和孔隙结构的药物缓释组织工程支架--三维大孔支架,提供能促进多能干细胞生长的微环境.设计:重复测量设计.单位:广州中医药大学基础医学院解剖教研室.材料:实验所用健康成年 SD 大鼠由广州中医药大学实验动物中心提供.壳聚糖、碱性成纤维细胞生长因子购自Sigma公司.方法:实验于2003-03/2006-12主要在广州中医药大学基础医学院解剖教研室完成.采用冷冻干燥的方法,用不同比例的壳聚糖.碱性成纤维细胞生长因子-明胶依次混匀,通过控制冷冻、复温和干燥时间处理使其具有最佳孔隙率和孔结构,制备具缓释碱性成纤维细胞生长因子功能的三维大孔支架.取SD大鼠股骨和胫骨骨髓,分离、培养骨髓间充质干细胞并移植于缓释碱性成纤维细胞生长因子的三维大孔支架上进行三维培养,与无碱性成纤维细胞生长因子的支架对照.实验过程中对动物的处置符合动物伦理学标准.主要观察指标:用ELISA和扫描电镜观察支架的三维结构和缓释性能,用苏木精-伊红染色、MTT、细胞计数及扫描电镜方法观察缓释碱性成纤维细胞生长因子的三维大孔支架对骨髓间充质干细胞生长状态和细胞活力的影响.结果:含有碱性成纤维细胞生长因子的三维大孔支架有碱性成纤维细胞生长因子缓释性能,孔隙尺寸与不含碱性成纤维细胞生长因子的支架三维结构相比,差异无显著性意义(P＞0.05).含有碱性成纤维细胞生长因子的三维大孔支架能提高在支架上立体培养的骨髓间充质干细胞存活率,促进骨髓间充质干细胞黏附、增殖和活力,与不含碱性成纤维细胞生长因子的支架相比,差异有显著性意义(P＜0.05).结论:含有碱性成纤维细胞生长因子的三维大孔支架能缓释碱性成纤维细胞生长因子,有利于在支架上立体培养的骨髓间充质干细胞存活,为其在组织工程中的应用打下基础.

In vitro proliferation of mesenchymal stem cells on three-dimensional macroporous scaffolds of chitosan-gelatin-basic fibroblast growth factor composite

BACKGROUND: Stem cell differentiation potential is strongly correlated with culture condition. The alteration in scaffold material surface function, three dimensional (3D) structure, and addition of growth factors can control stem cell proliferation and differentiation.OBJECTIVE: To develop 3D macroporous scaffolds with optimal porosity and porous structure to provide a microenvironment that promotes the growth of multi-potent stem cells.DESIGN: Repetitive measurement.SETTING: Department of Anatomy, College of Basic Medicine, Guangzhou University of Chinese Medicine.MATERIALS: Healthy adult SD rats were provided by the Experimental Animal Center in Guangzhou University of Chinese Medicine. Chitosan and basic fibroblast growth factor (bFGF) were purchased from Sigma Corporation (St. Louis,MO).METHODS: The experiment was performed at the Department of Anatomy, College of Basic Medicine, Guangzhou University of Chinese Medicine from March 2003 to December 2006. Using a freeze-drying method, 3D macroporous scaffolds made of different ratios of chitosan-gelatin with bFGF were fabricated that could release bFGF with controlled porosity and porous structure. Bone marrow was obtained from the femur and tibia of SD rats, and mesenchymal stem cells (MSCs) were isolated, cultured and seeded on the scaffolds with bFGF. MSCs seeded on scaffolds with no bFGF served as control. The procedure during experiment was accorded with animal ethical requirements.MAIN OUTCOME MEASURES: 3D structure and release performance of the scaffolds were observed by ELISA and scanning electron microscope; the effect of 3D macroporous scaffolds that released bFGF on MSC growth and viability were observed by HE staining, MTT, cell counting and SEM.RESULTS: There was no significant difference in pore size between scaffolds with and without bFGF (P ＞ 0.05). Scaffolds with bFGF significantly improved MSC survival rate, promoted cell adhesion, proliferation, and viability compared with scaffolds without bFGF (P ＜ 0.05).CONCLUSION: The results suggest that 3D macroporous scaffolds with bFGF release improve MSC survival on scaffolds,and lay a foundation for its application in tissue engineering.