Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
Stem Cells Dev. 2012 Jul 1;21(10):1701-15. doi: 10.1089/scd.2011.0509. Epub 2011 Dec 23.
While defining the environment for human embryonic stem cell (hESC) culture on 2-dimensional (2D) surfaces has made rapid progress, the industrial-scale implementation of this technology will benefit from translating this knowledge into a 3-dimensional (3D) system, thus enabling better control, automation, and volumetric scale-up in bioreactors. The current study describes a system with defined conditions that are capable of supporting the long-term 2D culture of hESCs and the transposing of these conditions to 3D microcarrier (MC) cultures. Vitronectin (VN) and laminin (LN) were chosen as matrices for the long-term propagation of hESCs in a defined culture medium (STEMPRO(®)) for conventional 2D culture. Adsorption of these proteins onto 2D tissue culture polystyrene (TCPS) indicated that surface density saturation of 510 and 850 ng/cm(2) for VN and LN, respectively, was attained above 20 μg/mL deposition solution concentration. Adsorption of these proteins onto spherical (97±10 μm), polystyrene MC followed a similar trend and coating surface densities of 450 and 650 ng/cm(2) for VN and LN, respectively, were used to support hESC propagation. The long-term expansion of hESCs was equally successful on TCPS and MC, with consistently high expression (>90%) of pluripotent markers (OCT-4, MAB-84, and TRA-1-60) over 20 passages and maintenance of karyotypic normality. The average fold increase in cell numbers on VN-coated MC per serial passage was 8.5±1.0, which was similar to LN-coated MC (8.5±0.9). Embryoid body differentiation assays and teratoma formation confirmed that hESCs retained the ability to differentiate into lineages of all 3 germ layers, thus demonstrating the first translation to a fully defined MC-based environment for the expansion of hESCs.
虽然在二维(2D)表面上定义人类胚胎干细胞(hESC)培养环境已经取得了快速进展,但将这一知识转化为三维(3D)系统将使该技术在工业规模上得到更广泛的应用,从而能够更好地控制、自动化和扩大生物反应器的体积。本研究描述了一种具有明确条件的系统,该系统能够支持 hESC 的长期 2D 培养,并将这些条件转化为 3D 微载体(MC)培养。选择纤连蛋白(VN)和层粘连蛋白(LN)作为基质,在传统的 2D 培养中使用定义的培养基(STEMPRO®)来长期增殖 hESC。这些蛋白质在 2D 组织培养聚苯乙烯(TCPS)上的吸附表明,VN 和 LN 的吸附表面密度分别达到 510 和 850ng/cm²时,沉积溶液浓度超过 20μg/mL。这些蛋白质在球形(97±10μm)、聚苯乙烯 MC 上的吸附也呈现出类似的趋势,VN 和 LN 的涂层表面密度分别为 450 和 650ng/cm²,用于支持 hESC 的增殖。hESC 的长期扩增在 TCPS 和 MC 上同样成功,多能标记物(OCT-4、MAB-84 和 TRA-1-60)的表达始终保持在 90%以上,超过 20 代,并保持核型正常。每传代 VN 包被 MC 上细胞数量的平均倍增数为 8.5±1.0,与 LN 包被 MC(8.5±0.9)相似。类胚体分化试验和畸胎瘤形成证实 hESC 保留了向所有 3 个胚层谱系分化的能力,从而首次将其转化为完全定义的基于 MC 的 hESC 扩增环境。