Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Fukuoka, 819-0395, Japan.
Department of Chemical and Biological Engineering, National Institute of Technology, Sasebo College, Okishin-cho, Sasebo, Nagasaki, 857-1193, Japan.
Sci Rep. 2020 Apr 21;10(1):6710. doi: 10.1038/s41598-020-63362-4.
In this report, a strategy for constructing three-dimensional (3D) cellular architectures comprising viable cells is presented. The strategy uses a redox-responsive hydrogel that degrades under mild reductive conditions, and a confluent monolayer of cells (i.e., cell sheet) cultured on the hydrogel surface peels off and self-folds to wrap other cells. As a proof-of-concept, the self-folding of fibroblast cell sheet was triggered by immersion in aqueous cysteine, and this folding process was controlled by the cysteine concentration. Such folding enabled the wrapping of human hepatocellular carcinoma (HepG2) spheroids, human umbilical vein endothelial cells and collagen beads, and this process improved cell viability, the secretion of metabolites and the proliferation rate of the HepG2 cells when compared with a two-dimensional culture under the same conditions. A key concept of this study is the ability to interact with other neighbouring cells, providing a new, simple and fast method to generate higher-order cellular aggregates wherein different types of cellular components are added. We designated the method of using a cell sheet to wrap another cellular aggregate the 'cellular Furoshiki'. The simple self-wrapping Furoshiki technique provides an alternative approach to co-culture cells by microplate-based systems, especially for constructing heterogeneous 3D cellular microstructures.
在本报告中，提出了一种构建由活细胞组成的三维（3D）细胞结构的策略。该策略使用了一种对氧化还原反应敏感的水凝胶，在温和的还原条件下会降解，而培养在水凝胶表面的连续单层细胞（即细胞片）会剥落并自行折叠，以包裹其他细胞。作为概念验证，通过将成纤维细胞片浸泡在含有半胱氨酸的水溶液中，触发了细胞片的自折叠，并且折叠过程可以通过半胱氨酸浓度来控制。这种折叠方式可以包裹人肝癌细胞（HepG2）球体、人脐静脉内皮细胞和胶原珠，并且与相同条件下的二维培养相比，该过程提高了 HepG2 细胞的存活率、代谢物分泌和增殖率。本研究的一个关键概念是与其他邻近细胞相互作用的能力，为生成更高阶的细胞聚集体提供了一种新的、简单和快速的方法，其中可以添加不同类型的细胞成分。我们将使用细胞片包裹另一个细胞聚集体的方法命名为“细胞袱紗”。简单的自包裹袱紗技术为基于微孔板的系统提供了一种共培养细胞的替代方法，特别是用于构建异质 3D 细胞微结构。
