Liu Yarong, Fox Victoria, Lei Yuning, Hu Biliang, Joo Kye-Il, Wang Pin
Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California.
J Biomed Mater Res B Appl Biomater. 2014 Jul;102(5):1101-12. doi: 10.1002/jbm.b.33092. Epub 2013 Dec 10.
The unique self-renewal and pluripotency features of human embryonic stem cells (hESCs) offer the potential for unlimited development of novel cell therapies. Currently, hESCs are cultured and differentiated using methods, such as monolayer culture and embryoid body (EB) formation. As such, achieving efficient differentiation into higher order structures remains a challenge, as well as maintaining cell viability during differentiation into homogeneous cell populations. Here, we describe the application of highly porous polymer scaffolds as synthetic stem cell niches. Bypassing the EB formation step, these scaffolds are capable of three-dimensional culture of undifferentiated hESCs and subsequent directed differentiation into three primary germ layers. H9 hESCs were successfully maintained and proliferated in biodegradable polymer scaffolds based on poly (lactic-co-glycolic acid) (PLGA). The results showed that cells within PLGA scaffolds retained characteristics of undifferentiated pluripotent stem cells. Moreover, the scaffolds allowed differentiation towards the lineage of interest by the addition of growth factors to the culture system. The in vivo transplantation study revealed that the scaffolds could provide a microenvironment that enabled hESCs to interact with their surroundings, thereby promoting cell differentiation. Therefore, this approach, which provides a unique culture/differentiation system for hESCs, will find its utility in various stem cell-based tissue-engineering applications.
人类胚胎干细胞（hESCs）独特的自我更新和多能性特征为新型细胞疗法的无限发展提供了潜力。目前，hESCs采用单层培养和胚状体（EB）形成等方法进行培养和分化。因此，实现高效分化为更高阶结构以及在分化为同质细胞群体过程中维持细胞活力仍然是一项挑战。在此，我们描述了高度多孔聚合物支架作为合成干细胞微环境的应用。绕过EB形成步骤，这些支架能够对未分化的hESCs进行三维培养，并随后定向分化为三个原始胚层。H9 hESCs在基于聚（乳酸-乙醇酸共聚物）（PLGA）的可生物降解聚合物支架中成功维持并增殖。结果表明，PLGA支架内的细胞保留了未分化多能干细胞的特征。此外，通过向培养系统中添加生长因子，支架允许向感兴趣的谱系分化。体内移植研究表明，支架可以提供一个微环境，使hESCs能够与周围环境相互作用，从而促进细胞分化。因此，这种为hESCs提供独特培养/分化系统的方法将在各种基于干细胞的组织工程应用中发挥作用。
