Nanofibers promote HepG2 aggregate formation and cellular function.

Formation of hepatocyte spheroids is a necessary strategy for increasing liver-specific function in vitro. In this study, HepG2 cells showed good viability when grown on a polylactic acid-chitosan (PLA-CS) nanofiber and aggregated to form multicellular spheroids on the PLA-CS nanofibers with a diameter of approximately 100-200 mm in 5 days of culture, whereas no such aggregation was observed in cells cultured on 24-well plates. Hepatocyte spheroids formed on the PLA-CS nanofibers displayed excellent hepatic-related protein expression, such as albumin and urea, compared to HepG2 cells cultured on the 24-well plates. These results indicated that formation of the hepatocyte spheroids in nanofibers can increase and maintain hepatocyte functions for a longer time, supporting a new strategy for bioartificial liver development.