Bilirubin, a Physiological Antioxidant, Can Improve Cryopreservation of Human Hepatocytes

ABSTRACT The availability of cryopreserved hepatocytes is required for a more widespread use of hepatocyte transplantation, but human hepatocytes are easily damaged during freezing‐thawing. Here, preincubation with unconjugated bilirubin, a physiological antioxidant, resulted in increased viability and function of hepatocytes (as determined by trypan blue exclusion, mitochondrial succinate dehydrogenases activity, urea synthesis, and cytochrome P450 1A/2) compared with cells incubated without the pigment. These findings suggest that unconjugated bilirubin may be used as cryoprotectant in clinical hepatocyte transplantation.