Efficient hepatic differentiation of human induced pluripotent stem cells in a three-dimensional microscale culture

Human induced pluripotent stem cells (iPSCs) represent a novel source of hepatocytes for drug development, disease modeling studies, and regenerative therapy for the treatment of liver diseases. A number of protocols for generating functional hepatocytes have been reported worldwide; however, reproducible and efficient differentiation remained challenging under conventional two-dimensional (2D) culture. In this study, we describe an efficient differentiation protocol for generating functional hepatocyte-like cells from human iPSC-derived homogenous hepatic endoderm cells combined with three-dimensional (3D) microscale culture system. First, hepatic endoderm cells (iPSC-HEs) were directly differentiated using two-step approaches, and then cultured in the 3D micropattern plate. Human iPSC-HEs quickly reaggregated and formed hundreds of round-shaped spheroids at day 4 of cell plating. The size distribution of iPSC-HEs derived spheroids was relatively uniform around 100-200 μm in diameter. After 14 days, iPSC-HEs efficiently differentiated into hepatocyte-like cells in terms of hepatic maker gene expression compared with conventional 2D approach. We conclude that our scalable and three-dimensional culture system would be one promising approach to generate a huge number of hepatocyte-like cells from human iPSCs aiming at future industrial and clinical applications.