Department of Chemistry and Biotechnology, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia; CSIRO Manufacturing, Research Way, Clayton, Victoria 3168, Australia.
Department of Chemistry and Biotechnology, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
Colloids Surf B Biointerfaces. 2020 Oct;194:111133. doi: 10.1016/j.colsurfb.2020.111133. Epub 2020 May 15.
Understanding the interactions of stem cells with surface topography can give us an invaluable tool in controlling stemness and fate of stem cells for further use in biomedical applications. In this study, we have fabricated topographical features using a class of cell culture substrates called binary colloidal crystals (BCCs), that are made by self-assembly of mixtures of spherical micron sized silica (Si) and nanometer sized polystyrene (PS) or poly (methyl methacrylate) (PMMA) particles. The substrates formed are arrays of ordered, hexagonally packed large Si particles inter-dispersed with the PS particles that are stabilized by gentle heating, which melts the PS or PMMA forming substrates suitable for cell culture. BCC substrates were used for culture of mouse embryonic stem cells (mESCs). Compared to tissue culture plates, COM1 (Si5-PMMA0.4), COM2 (Si5-PS0.4) and COM4 (Si2-PSC0.22) have shown to provide a better support for mESC proliferation in the presence of the cytokine leukemia inhibitory factor (LIF). The behavior of mESCs with the BCCs in presence and absence of LIF, was further explored and it was found that interaction of mESCs with the culture substrate can be controlled by tuning surface topography and roughness, which is determined by the size and type of particles used in making BCCs. Furthermore, it was shown that limiting cell-surface interactions and controlling colony shape can promote stemness maintenance on COM1 and COM2 substrates as indicated by better proliferation and higher expression of pluripotency genes including Nanog both in presence and in absence of LIF. Together with higher expression of GATA6 gene, it can be stated that these surfaces can be used for endodermic priming of mESCs. Therefore, we believe that these surfaces, especially COM1 and COM2 surfaces can be beneficial as stem cell culture systems for further use in biomedical research.
了解干细胞与表面形貌的相互作用，可以为我们提供一种非常有价值的工具，用于控制干细胞的干性和命运，以便进一步应用于生物医学领域。在这项研究中，我们使用一类称为二元胶体晶体（BCC）的细胞培养底物来制造形貌特征，这些晶体是由混合的球形微米级二氧化硅（Si）和纳米级聚苯乙烯（PS）或聚甲基丙烯酸甲酯（PMMA）颗粒自组装而成的。形成的基底是有序的、六边形排列的大 Si 颗粒阵列，其中分散着 PS 颗粒，这些 PS 颗粒通过温和加热稳定，这会熔化 PS 或 PMMA，形成适合细胞培养的基底。BCC 基底用于培养小鼠胚胎干细胞（mESCs）。与组织培养板相比，COM1（Si5-PMMA0.4）、COM2（Si5-PS0.4）和 COM4（Si2-PSC0.22）在存在细胞因子白血病抑制因子（LIF）的情况下，更有利于 mESC 的增殖。进一步探索了 mESCs 在有无 LIF 的情况下与 BCC 的相互作用行为，结果发现，通过调整表面形貌和粗糙度，可以控制 mESCs 与培养基底的相互作用，而表面形貌和粗糙度则由制造 BCC 时使用的颗粒的大小和类型决定。此外，研究结果表明，限制细胞-表面相互作用并控制集落形状可以促进 COM1 和 COM2 基底上的干性维持，这表现为在有或没有 LIF 的情况下，增殖能力更好，多能性基因（包括 Nanog）的表达水平更高。与 GATA6 基因的高表达相结合，可以表明这些表面可用于 mESCs 的内胚层诱导。因此，我们认为这些表面，尤其是 COM1 和 COM2 表面，可用作干细胞培养系统，进一步应用于生物医学研究。
