Figure 2

Screening approaches. (A) Differentiation of induced pluripotent stem (iPS) cells into hepatocytes, by recapitulating normal stages of liver development (the same strategy is pursued for iPS cardiomyocytes). Hepatocyte-like cells derived this way still have a fetal phenotype. (B) To mature the cells, we designed a small molecule screen where we treated iPS cell-derived hepatocytes (iHeps) from day 20 of the differentiation for 9 days, and found a few molecules that improved the maturation of iPS cell-derived hepatocytes. (C) Results are for the top hit of small-molecule screening. (D) Aggregates of cryopreserved primary human hepatocytes (~5 hepatocytes/5 fibroblasts per aggregate) are microfluidically encapsulated into uniform droplets in a microfluidic device, and photopolymerized to form microtissues. (E) Viable cells in liver microtissues (scale bar = 100 μm). bFGF, basic fibroblast growth factor; BMP4, bone morphogenetic protein 4; ELISA, enzyme-linked immunosorbent assay; HGF, hepatocyte growth factor; OSM, oncostatin M; (C) Image reproduced with permission [16].