Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
Karlsruhe Institute of Technology (KIT), Zoological Institute, Cell- and Neurobiology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany.
Adv Healthc Mater. 2017 Dec;6(23). doi: 10.1002/adhm.201700622. Epub 2017 Sep 29.
Over the past decades, stem cells have attracted growing interest in fundamental biological and biomedical research as well as in regenerative medicine, due to their unique ability to self-renew and differentiate into various cell types. Long-term maintenance of the self-renewal ability and inhibition of spontaneous differentiation, however, still remain challenging and are not fully understood. Uncontrolled spontaneous differentiation of stem cells makes high-throughput screening of stem cells also difficult. This further hinders investigation of the underlying mechanisms of stem cell differentiation and the factors that might affect it. In this work, a dual functionality of nanoporous superhydrophobic-hydrophilic micropatterns is demonstrated in their ability to inhibit differentiation of mouse embryonic stem cells (mESCs) and at the same time enable formation of arrays of microdroplets (droplet microarray) via the effect of discontinuous dewetting. Such combination makes high-throughput screening of undifferentiated mouse embryonic stem cells possible. The droplet microarray is used to investigate the development, differentiation, and maintenance of stemness of mESC, revealing the dependence of stem cell behavior on droplet volume in nano- and microliter scale. The inhibition of spontaneous differentiation of mESCs cultured on the droplet microarray for up to 72 h is observed. In addition, up to fourfold increased cell growth rate of mESCs cultured on our platform has been observed. The difference in the behavior of mESCs is attributed to the porosity and roughness of the polymer surface. This work demonstrates that the droplet microarray possesses the potential for the screening of mESCs under conditions of prolonged inhibition of stem cells' spontaneous differentiation. Such a platform can be useful for applications in the field of stem cell research, pharmacological testing of drug efficacy and toxicity, biomedical research as well as in the field of regenerative medicine and tissue engineering.
在过去的几十年中，由于其独特的自我更新和分化为各种细胞类型的能力，干细胞在基础生物学和生物医学研究以及再生医学中引起了越来越多的关注。然而，长期维持自我更新能力和抑制自发分化仍然具有挑战性，并且尚未完全了解。干细胞的不受控制的自发分化使得高通量筛选干细胞也变得困难。这进一步阻碍了对干细胞分化的潜在机制以及可能影响其分化的因素的研究。在这项工作中，展示了纳米多孔超疏水-亲水微图案的双重功能，即能够抑制小鼠胚胎干细胞 (mESC) 的分化，同时通过不连续去湿的作用使微滴阵列 (微滴微阵列) 形成。这种组合使得未分化的小鼠胚胎干细胞的高通量筛选成为可能。使用微滴微阵列研究 mESC 的发育、分化和干性维持，揭示了在纳米和微升尺度上干细胞行为对液滴体积的依赖性。观察到在微滴微阵列上培养的 mESC 自发分化长达 72 小时的抑制。此外，还观察到在我们的平台上培养的 mESC 的细胞生长速率提高了高达四倍。mESC 行为的差异归因于聚合物表面的多孔性和粗糙度。这项工作表明，微滴微阵列具有在长期抑制干细胞自发分化的条件下筛选 mESC 的潜力。该平台可用于干细胞研究、药物功效和毒性的药理学测试、生物医学研究以及再生医学和组织工程领域的应用。
