Gene expression profiles of HYDROX-cultured human liver organoids compared to those of Matrigel-cultured human liver organoids.

Human liver organoids, an in vitro 3D culture system to recapitulate biological tissue, are expected to be used for drug discovery. However, Matrigel, the most widely used extracellular matrix for organoid culture, has concerns about safety and reproducibility since it is murine-derived. Morever, low hepatic functions of human liver organoids compared to primary human hepatocytes is considered a challenge. Herein, we attempted to culture human liver organoids, established from primary (cryopreserved) human hepatocytes (PHH), using HYDROX, a chemically defined 3D nanofiber. While proliferative capacity of human liver organoids was lost by HYDROX-culture, the gene expression level of a hepatocyte marker CYP3A4 and the CYP3A4 metabolic activity in HYDROX-cultured liver organoids were significantly improved, comparable to those of PHH. HYDROX-cultured liver organoids when treated with hepatotoxic drugs such as acetaminophen showed similar cell viability to that of PHH, suggesting that HYDROX-cultured liver organoids could be applied to drug-induced hepatotoxicity test. Furthermore, HYDROX-cultured liver organoids maintained its functions for up to 35 days and could be used to estimate chronic drug-induced hepatotoxicity such as those of fialuridine. Our findings demonstrated that human liver organoids obtained high liver functions by HYDROX-culture, meaning that HYDROX could contribute to drug discovery as a novel biomaterial.