Lou Yan-Ru, Kanninen Liisa, Kaehr Bryan, Townson Jason L, Niklander Johanna, Harjumäki Riina, Jeffrey Brinker C, Yliperttula Marjo
Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, the University of Helsinki, Helsinki 00014, Finland.
Advanced Materials Laboratory, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Sci Rep. 2015 Sep 1;5:13635. doi: 10.1038/srep13635.
Three-dimensional (3D) cell cultures produce more in vivo-like multicellular structures such as spheroids that cannot be obtained in two-dimensional (2D) cell cultures. Thus, they are increasingly employed as models for cancer and drug research, as well as tissue engineering. It has proven challenging to stabilize spheroid architectures for detailed morphological examination. Here we overcome this issue using a silica bioreplication (SBR) process employed on spheroids formed from human pluripotent stem cells (hPSCs) and hepatocellular carcinoma HepG2 cells cultured in the nanofibrillar cellulose (NFC) hydrogel. The cells in the spheroids are more round and tightly interacting with each other than those in 2D cultures, and they develop microvilli-like structures on the cell membranes as seen in 2D cultures. Furthermore, SBR preserves extracellular matrix-like materials and cellular proteins. These findings provide the first evidence of intact hPSC spheroid architectures and similar fine structures to 2D-cultured cells, providing a pathway to enable our understanding of morphogenesis in 3D cultures.
三维（3D）细胞培养可产生更多类似体内的多细胞结构，如球体，而二维（2D）细胞培养无法获得此类结构。因此，它们越来越多地被用作癌症和药物研究以及组织工程的模型。事实证明，稳定球体结构以进行详细的形态学检查具有挑战性。在这里，我们使用一种二氧化硅生物复制（SBR）工艺克服了这一问题，该工艺应用于由在纳米纤维纤维素（NFC）水凝胶中培养的人多能干细胞（hPSC）和肝癌HepG2细胞形成的球体。与二维培养中的细胞相比，球体中的细胞更呈圆形且彼此紧密相互作用，并且它们在细胞膜上形成了类似于二维培养中所见的微绒毛样结构。此外，SBR保留了细胞外基质样物质和细胞蛋白质。这些发现首次证明了完整的hPSC球体结构以及与二维培养细胞相似的精细结构，为我们理解三维培养中的形态发生提供了一条途径。
