Effective cryopreservation and long-term storage of primary human hepatocytes with recovery of viability, differentiation, and replicative potential.

Despite reports of successful cryopreservation of primary human hepatocytes, existing methods do not produce sufficient recovery of viable cells to meet the needs of basic research or clinical trials of hepatocellular transplantation. We now describe a protocol for efficient cryopreservation of primary human hepatocytes using University of Wisconsin (UW) solution, fetal bovine serum, and dimethyl sulfoxide (DMSO). This method provides > 90% viability of differentiated, primary human hepatocytes 8 mo after cryopreservation as measured by trypan blue exclusion, preserves hepatocyte morphology, liver-specific gene expression (alpha 1 antitrypsin), and replication. The effectiveness of UW solution as a cryopreservative agent suggests that metabolic as well as ultrastructural factors may be important in the effective cryopreservation of primary human hepatocytes. The present method represents an effective protocol for cryopreserving differentiated primary human hepatocytes for research. This method may allow characterization and banking of human hepatocytes for clinical applications, including hepatocellular transplantation and hepatic assist devices.