Differentiation of human-induced pluripotent stem cells into hepatocytes-like cells in 3D culture using functional polymers

Suspension culture is superior to planar culture in efficiently growing large numbers of cells. It also greatly improves cell functions by mimicking the in vivo environment. Although several methods are available to differentiate human induced pluripotent stem (iPS) cells into hepatocyte-like cells, their differentiation by suspension culture by using functional polymers remains unreported. We developed a suspension culture system using the functional polymers FP001 and FP003 to generate hepatocyte-like cells with superior phenotypes than human iPS cell-derived hepatocyte-like cells generated in planar culture. Specifically, optimizing the initial spheroid size and utilizing FP003 effectively maintained appropriate spheroid structures, resulting in higher albumin production compared to FP001. In 3D sphere culture, the mRNA expression of albumin (ALB), drug-metabolizing enzymes and transporters, and the activity of CYP1A2 were increased in the presence of 0.01% FP003. Additionally, immunofluorescence analysis confirmed uniform hepatic differentiation throughout the spheroids. These findings suggest that differentiation in 3D sphere culture with the functional polymer FP003 improved the function of human iPS cell-derived hepatocyte-like cells. Therefore, we conclude that this system may be an effective strategy to generate human iPS cell-derived hepatocyte-like cells with enhanced functions.