Human hepatocyte cultures on gas foaming templated alginate scaffolds for in vitro drug-drug interaction and metabolism studies

Liver in vitro systems that allow reliable prediction of major human in vivo metabolic pathways have a significant impact in drug screening and drug metabolism research. In the present study, a novel porous scaffold composed of alginate was prepared by employing a gas-in-liquid foaming approach. Galactose residues were introduced on scaffold surfaces to promote cell adhesion and to enhance liver specific functions of the entrapped HepG2/C3A cells. Hepatocytes in the gal-alginate scaffold showed higher levels of liver specific products and were more responsive to specific inducers and inhibitors of the CYP3A4 system than hepatocytes in conventional monolayer culture. HepG2/C3A cells were also more efficient in terms of rapid elimination of testosterone, used as a model substance, at rates comparable to those of in vivo excretion. In addition, an improvement in metabolism of testosterone, in terms of phase II metabolite formation, was also observed when the more differentiated HepaRG cells were used. The formation of these metabolites was also greater in cells cultured on alginate scaffolds than in monolayer. Together the data suggest that hepatocyte/gas templated alginate-systems provide an innovative high throughput platform for in vitro drug metabolism and drug-drug interaction studies with broad fields of application, such as in toxicology studies, in pharmaceutical industry and in anti-doping research. Moreover, they may provide a valid tool for minimizing animal use in preclinical testing of human relevance.