人诱导性多能干细胞的无饲养层培养及鉴定

目的：探索人诱导性多能干细胞（induced pluripotent stem cells,iPSCs）的无饲养层培养方法,并对此方法培养的iPSCs进行鉴定。方法将人iPSCs接种于玻璃粘连蛋白（Vitronectin XF）包被的培养皿上培养,采用EDTA消化传代。倒置显微镜下观察iPSCs的生长状态;碱性磷酸酶（ALP）染色鉴定;采用PCR和免疫荧光检测iPSCs多能性基因SSEA?1、Nanog、Sox2的表达情况。结果倒置显微镜下可见iPSCs呈典型的克隆状生长,克隆呈圆形或椭圆形,边界清晰、整齐;ALP染色结果阳性;PCR结果显示人iPSCs强表达多能性基因SSEA?1、Nanog、Sox2;免疫荧光结果显示多能干细胞特异性指标SSEA?1、Nanog、Sox2均呈阳性。结论无饲养层培养体系培养人iPSCs,细胞能稳定增殖,保持自我更新潜能及多能性。     

Bio-inspired oligovitronectin-grafted surface for enhanced self-renewal and long-term maintenance of human pluripotent stem cells under feeder-free conditions

Current protocols for human pluripotent stem cell (hPSC) expansion require feeder cells or matrices from animal sources that have been the major obstacle to obtain clinical grade hPSCs due to safety issues, difficulty in quality control, and high expense. Thus, feeder-free, chemically defined synthetic platforms have been developed, but are mostly confined to typical polystyrene culture plates. Here, we report a chemically defined, material-independent, bio-inspired surface coating allowing for feeder-free expansion and maintenance of self-renewal and pluripotency of hPSCs on various polymer substrates and devices. Polydopamine (pDA)-mediated immobilization of vitronectin (VN) peptides results in surface functionalization of VN-dimer/pDA conjugates. The engineered surfaces facilitate adhesion, proliferation, and colony formation of hPSCs via enhanced focal adhesion, cell–cell interaction, and biophysical signals, providing a chemically defined, xeno-free culture system for clonal expansion and long-term maintenance of hPSCs. This surface engineering enables the application of clinically-relevant hPSCs to a variety of biomedical systems such as tissue-engineering scaffolds and medical devices.     

两株人胚胎干细胞的无饲养层扩增

目的:建立两株中国人胚胎干细胞(hESCs)的无饲养层的培养体系,观察条件培养基所需的饲养层密度,并探索最佳的传代方式。方法:两株人胚胎干细胞hES-846XX和hES-1846XY分别使用不同密度(3×105/mL、6×105/mL和1.2×106/mL)获得的条件培养基(CM)在无饲养层培养体系培养12代以上,用机械分离法和Ⅳ型胶原酶法进行传代,观察比较结果并对所得hESCs鉴定。结果:6×105/mL～1.2×106/mL之间的密度都是合适密度;Ⅳ型胶原酶在长期传代中优于机械法传代;所得细胞维持干细胞未分化状态和全能性。结论:无饲养层的培养体系可以用于中国胚胎干细胞培养,两株中国人胚胎干细胞(hESCs)的倍增周期、所需饲养层密度及分化率等方面与国外hESCs有明显差别。     

诱导人胚胎干细胞向子宫内膜样细胞分化的初步研究

目的:探讨无饲养层培养的人胚胎干细胞诱导分化为子宫内膜样细胞的方法。方法:将无饲养层培养的人胚胎干细胞分别通过共培养诱导法和细胞因子诱导法向子宫内膜样细胞诱导,流式细胞术检测分化的细胞中子宫内膜上皮细胞标志物细胞角蛋白18和间质细胞标志物波形蛋白的表达情况。结果:共培养诱导法和细胞因子诱导法在分化第7天均出现长梭状细胞样改变。分化第8天通过流式细胞术检测发现细胞波形蛋白表达均为阴性,部分细胞角蛋白18表达阳性,共培养诱导法分化率高于细胞因子诱导法[(55.63±10.29)%vs.(13.90±0.26)%,P<0.05]。结论:共培养诱导法和细胞因子诱导法均可使人胚胎干细胞分化为子宫内膜上皮样细胞,但前者的分化效率更高。