Maintenance of human hepatocytes metabolism in culture using a newly-formulated solid shipping medium

Research on metabolism is a key issue during the development of a new pharmaceutical, since it can play a determining role in inter-individual pharmacokinetic differences, clinical efficacy and the toxicity of drugs. Cultured... [ view full abstract ]

Research on metabolism is a key issue during the development of a new pharmaceutical, since it can play a determining role in inter-individual pharmacokinetic differences, clinical efficacy and the toxicity of drugs. Cultured primary hepatocytes are currently the gold standard model for in vitro metabolism studies. Cells contain phase I and II metabolic enzymes and do not need to be supplied with exogenous cofactors to reach a drug metabolic process. On the contrary, isolated hepatocytes rapidly lose their metabolic capacities over time in culture which limits their complex adaptive responses to chemical exposure. This limitation is especially remarkable for human hepatocytes based on the poor availability of human tissue. 

To circumvent this issue, we investigated whether Readycell’s patented solid shipping medium (SM) might preserve over time the integrity of constitutive phase I and II enzyme metabolic capacities in cultured human hepatocytes. Initially, cells from six different donors were incubated up to 96 h in the absence/presence of the SM. Despite human metabolic idiosyncracy, data indicated that SM preserved at least 2-fold the activity of most of the CYP isoforms, especially after 48-h incubation. Additional experiments to test CYP and UDP-glucuronyl transferase (UGT) activities for longer periods of time (7 days) with new human donors (n=7) showed that hepatocytes were metabolically active even after a week in culture. Activities were proven to be sufficient to perform ADMETox studies, including enzyme induction.

Overall data indicate that tested shipping medium preserves human hepatocyte functionality over time having a potential use for worldwide-cell distribution.