A serum-free medium suitable for maintaining cell morphology and liver-specific function in induced human hepatocytes

hiHep is a new type of hepatocyte-like cell that is predicted to be a potential unlimited source of hepatocytes for a bioartificial liver. However, hiHep cannot currently be used in clinical settings because serum must be added during the culture process. Thus, a defined medium is required. Because serum is complex, an efficient statistical approach based on the Plackett-Burman design was used. In this manner, an original medium and several significant cell growth factors were identified. These factors include insulin, V_H, and V_E, and the original medium was optimized based on these significant factors. Additionally, hiHep liver-specific functions and metabolism in the optimized serum-free medium were measured. Results showed that hiHep functions, such as glycogen storage, albumin secretion, and urea production, were well maintained in our optimized serum-free medium. In summary, we created a chemically defined, serum-free medium in which cell growth, proliferation, metabolism, and function were well maintained. This medium has the potential to support the clinical use of hiHep.