Magyar J P, Nemir M, Ehler E, Suter N, Perriard J C, Eppenberger H M
Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, Zurich.
Ann N Y Acad Sci. 2001 Nov;944:135-43. doi: 10.1111/j.1749-6632.2001.tb03828.x.
Embryonic stem cells (ESC) are totipotent cells that can differentiate into a large number of different cell types. Stem cell-derived, differentiated cells are of increasing importance as a potential source for non-proliferating cells (e.g., cardiomyocytes or neurons) for future tissue engineering applications. Differentiation of ESC is initiated by the formation of embryoid bodies (EB). Current protocols for the generation of EB are either of limited productivity or deliver EB with a large variation in size and differentiation state. To establish an efficient and robust EB production process, we encapsulated mouse ESC into alginate microbeads using various microencapsulation technologies. Microencapsulation and culturing of ESC in 1.1% alginate microbeads gives rise to discoid colonies, which further differentiate within the beads to cystic EB and later to EB containing spontaneously beating areas. However, if ESC are encapsulated into 1.6% alginate microbeads, differentiation is inhibited at the morula-like stage, so that no cystic EB can be formed within the beads. ESC colonies, which are released from 1.6% alginate microbeads, can further differentiate to cystic EB with beating cardiomyocytes. Extended supplementation of the growth medium with retinoic acid promotes differentiation to smooth muscle cells.
胚胎干细胞（ESC）是全能细胞，能够分化为大量不同的细胞类型。干细胞衍生的分化细胞作为未来组织工程应用中不增殖细胞（如心肌细胞或神经元）的潜在来源，其重要性日益增加。ESC的分化是由胚状体（EB）的形成启动的。目前生成EB的方案要么生产率有限，要么产生大小和分化状态差异很大的EB。为了建立一个高效且稳健的EB生产过程，我们使用各种微囊化技术将小鼠ESC封装到藻酸盐微珠中。将ESC微囊化并在1.1%的藻酸盐微珠中培养会产生盘状集落，这些集落在微珠内进一步分化为囊性EB，随后分化为含有自发跳动区域的EB。然而，如果将ESC封装到1.6%的藻酸盐微珠中，分化在桑葚胚样阶段受到抑制，因此微珠内无法形成囊性EB。从1.6%的藻酸盐微珠中释放出来的ESC集落可以进一步分化为含有跳动心肌细胞的囊性EB。用视黄酸对生长培养基进行长期补充可促进向平滑肌细胞的分化。
