Biochemical and Biophysical Properties of Extracellular Matrix Nanofibers Modulate iPSC-Derived Human Hepatocyte...

Human liver models grown in the lab are used for testing drug metabolism and toxicity, studying liver diseases, and developing new therapies. Induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (HLCs) provide a renewable alternative to scarce primary human hepatocytes (PHHs), but they remain functionally immature compared to adult liver cells. The extracellular matrix (ECM) is a key regulator of liver cell behavior, yet how its biochemical makeup, stiffness, and structural organization work together to influence HLC maturation is not well understood. Here, we engineered electrospun nanofibers from collagen I, chitosan, porcine liver ECM (PLECM), and blends of these materials. Over 3 weeks of differentiation, HLCs cultured on ECM nanofibers showed more advanced functional maturation than those grown on standard Geltrex-coated substrates. Importantly, chitosan/collagen nanofibers promoted greater HLC function than either hydrogels of similar stiffness or proteins adsorbed to glass, highlighting the importance of nanoscale topography. By contrast, stiffer polyvinyl alcohol nanofibers of comparable size failed to enhance HLC maturation, a result linked to higher nuclear activity of the mechanosensor Yes-associated protein 1 (YAP). These findings demonstrate that ECM nanofibers drive more mature iPSC-HLCs and advance the development of predictive human liver models for drug discovery, disease modeling, and regenerative medicine.