Prince of Wales Hospital, School of Psychiatry, University of New South Wales, NSW, Australia.
Biomaterials. 2010 Jan;31(3):505-14. doi: 10.1016/j.biomaterials.2009.09.071. Epub 2009 Oct 14.
Human embryonic stem cells (hESCs) are potential renewable sources of cells in replacement therapies for many diseases including type 1 diabetes. We have established a three dimensional (3D) model to culture and differentiate hESCs that are encapsulated in calcium alginate microcapsules. This system promotes cellular interactions that are essential for both maintaining pluripotency and differentiation. This 3D model also provides opportunity to separate out hESCs from fibroblasts used as feeder layer during culture. In this study, we compared the viability and proliferation of the encapsulated hESCs cultured in serum replacement (SR) medium, human fetal fibroblast-conditioned medium (hFF-CM), in the presence and absence of Y-27632, a ROCK inhibitor. Treatment of hESCs with Y-27632 promoted cell survival, cell cluster formation and proliferation rate in both SR medium and hFF-CM. These encapsulated hESC clusters were then directly differentiated to definitive endoderm cells that expressed mesendoderm (Brachyury 70-fold), definitive endoderm (SOX17>300-fold, FOXA2>800-fold, and CXCR4>100-fold) and primitive gut tube (HNF1beta>120-fold) as compared to the undifferentiated hESCs. These data show that microcapsules can be used for differentiation of hESCs into definitive endoderm in 3D and could have potential application for immune-isolation and prevention of teratomas formation of hESCs during transplantation.
人类胚胎干细胞（hESCs）是许多疾病包括 1 型糖尿病替代疗法中细胞的潜在可再生来源。我们建立了一个三维（3D）模型，用于培养和分化包封在海藻酸钙微胶囊中的 hESCs。该系统促进了细胞间的相互作用，这对于维持多能性和分化都是必不可少的。该 3D 模型还提供了将 hESCs 从用作培养中饲养层的人胎儿成纤维细胞中分离出来的机会。在这项研究中，我们比较了在无血清替代（SR）培养基和人胎儿成纤维细胞条件培养基（hFF-CM）中培养的包封 hESCs 的活力和增殖情况，以及存在和不存在 ROCK 抑制剂 Y-27632 的情况。用 Y-27632 处理 hESCs 可促进细胞存活、细胞团形成和增殖率，无论是在 SR 培养基还是 hFF-CM 中。然后，这些包封的 hESC 簇直接分化为表达中胚层（Brachyury 70 倍）、明确内胚层（SOX17>300 倍，FOXA2>800 倍，CXCR4>100 倍）和原始肠管（HNF1beta>120 倍）的确定内胚层细胞与未分化的 hESCs 相比。这些数据表明，微胶囊可用于将 hESCs 分化为 3D 中的明确内胚层，并且在移植过程中用于免疫隔离和防止 hESCs 形成畸胎瘤方面具有潜在的应用。
