The behaviors of long-term cryopreserved human hepatocytes on different biomaterials.

Isolated human hepatocytes have been extensively investigated due to clinical demand and scientific interest. With a limited supply of available liver tissue and the rapid loss of liver-specific functions in vitro, cryopreservation of human hepatocytes serves as an alternative way to maintain availability of hepatocytes. The purpose of this study was to evaluate the biological behaviors of long-term (more than 4 years) cryopreserved human hepatocytes on biomaterials, including polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol), polyvinylidene fluoride, commercial tissue culture polystyrene (TCPS), and collagen-coated TCPS. Cell attachment was observed by scanning electron microscopy and quantified by lactate dehydrogenase assay. Cell viability was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction activity. Cell functions were determined by albumin secretion and urea synthesis. Results indicated that human hepatocytes could be cryopreserved for more than 4 years without losing liver-specific functions. Also, PVA was proposed to serve as an appropriate and promising substrate for culturing long-term cryopreserved hepatocytes, maintaining high cell attachment and high level of liver-specific functions.