Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
Biomaterials. 2011 Jul;32(20):4489-97. doi: 10.1016/j.biomaterials.2011.03.019. Epub 2011 Apr 8.
Cell replacement therapies, using renewable stem cell sources, hold tremendous potential to treat a wide range of degenerative diseases. Although many studies have established techniques to successfully differentiate stem cells into different mature cell lineages using growth factors or extracellular matrix protein supplementation in both two and three-dimensional configurations, they are often limited by lack of control and low yields of differentiated cells. Previously, we developed a scalable murine embryonic stem cell differentiation environment which maintained cell viability and supported ES cell differentiation to hepatocyte lineage cells. Differentiated hepatocyte function was contingent upon aggregate formation within the alginate microbeads. The present studies were designed to determine the feasibility of adapting the alginate encapsulation technique to neural lineage differentiation. The results of our studies indicate that by incorporating the soluble inducer, retinoic acid (RA), into the permeable microcapsule system, cell aggregation was decreased and neural lineage differentiation enhanced. In addition, we demonstrated that even in the absence of RA, differentiation could be directed away from the hepatocyte and toward the neural lineage by physical cell-cell aggregation blocking. In conjunction with the mechanical and physical characterization of the alginate crosslinking network, we determined that 2.2% alginate microencapsulation can be optimally adapted to ES neural differentiation. This study offers insights into targeting cellular differentiation toward both endodermal and ectodermal cell lineages, and could potentially be adaptable to differentiation of other stem cell types given the correct inducible factors and material properties.
细胞替代疗法使用可再生的干细胞来源，具有治疗多种退行性疾病的巨大潜力。虽然许多研究已经建立了技术，通过在二维和三维构型中使用生长因子或细胞外基质蛋白补充来成功地将干细胞分化为不同的成熟细胞谱系，但它们往往受到缺乏控制和分化细胞产量低的限制。此前，我们开发了一种可扩展的鼠胚胎干细胞分化环境，该环境保持细胞活力，并支持 ES 细胞分化为肝谱系细胞。分化的肝细胞功能取决于藻酸盐微珠内的聚集体形成。本研究旨在确定将藻酸盐包封技术适应于神经谱系分化的可行性。我们的研究结果表明，通过将可溶性诱导剂视黄酸 (RA) 纳入可渗透的微胶囊系统，可以减少细胞聚集并增强神经谱系分化。此外，我们证明，即使没有 RA，通过物理细胞-细胞聚集阻断，也可以将分化从肝细胞引导到神经谱系。结合藻酸盐交联网络的机械和物理特性，我们确定 2.2%的藻酸盐微囊化可以最佳地适应 ES 神经分化。这项研究为针对内胚层和外胚层细胞谱系的细胞分化提供了新的见解，并且如果有正确的诱导因子和材料特性，它可能适用于其他干细胞类型的分化。
