Comparative Analysis of Species-Specific Hepatocyte Function and Drug Effects in a Liver Microphysiological System PhysioMimix® LC12 and 96-Well Plates

Drug-induced liver injury (DILI) remains a major challenge in drug development and inter-species differences in potential liver toxicity are one area where comparative analyses may inform pre-clinical safety study design. In vitro testing for species-specific liver effects, especially in complex models such as microphysiological systems (MPS) may help predict toxicity before advancing from animal to human studies or de-risk spurious findings in pre-clinical species. This study assessed the utility of the perfusion-based PhysioMimix® LC12 MPS for evaluating species-specific DILI using primary hepatocytes from human, monkey, rat, and dog. First, functional, phenotypic, and transcriptional profiles were established over 2 weeks in cell culture. Then, cells were exposed to species-specific DILI compounds – chlorpromazine (CPZ), bosentan (BOS), and fialuridine (FIAU) – in both PhysioMimix® LC12 and traditional 2D cultures. Hepatocytes in PhysioMimix® LC12 showed more stable albumin and urea production for up to 14 days as compared to 2D cultures. Concentration-response studies with CPZ, BOS, or FIAU were performed in 2D; then, prolonged exposures (10 days) to sub-100× Cmax concentrations were tested in PhysioMimix® LC12. Species-specific differences in cellular and molecular effects of the drugs were observed in both models; data from PhysioMimix® LC12 were more reflective of the expected effects in whole animals or humans. Still, variability and low throughput are limitations of the MPS for prospective studies of species-specific responses. Overall, this study confirms the utility of liver safety studies using MPS, but also provides suggestions for experimental designs to overcome the limitations of more complex test systems.