Long-term survival and functional maintenance of hepatocytes by using a microfabricated cell array

We developed a microfabricated cell array of hepatocyte spheroids that showed long-term viability and retained the properties of the parent hepatocytes. Fresh hepatocytes harvested from 8-week-old Wistar rats were cocultured with feeder cells to rapidly form hepatocyte spheroids; these cells retained the spheroidal formation for 42 days. We also evaluated the cellular functions of the hepatocytes such as albumin secretion and metabolic activity of cytochrome P450 (CYP). In spheroids in which hepatocytes were cocultured with feeder cells, these cellular functions were retained even after 42 days. Therefore, this novel coculture will be very useful not only for research on the mechanism and treatment of liver diseases but also for early prediction of hepatocyte toxicity in the pre-clinical phase of drug development.