Microfluidic biochip for the perifusion of precision‐cut rat liver slices for metabolism and toxicology studies

Early detection of kinetic, metabolic, and toxicity (ADME‐Tox) profiles for new drug candidates is of crucial importance during drug development. This article describes a novel in vitro system for the incubation of precision‐cut liver slices (PCLS) under flow conditions, based on a poly(dimethylsiloxane) (PDMS) device containing 25‐µL microchambers for integration of the slices. The microdevice is coupled to a perifusion system, which enables a constant delivery of nutrients and oxygen and a continuous removal of waste products. Both a highly controlled incubation environment and high metabolite detection sensitivity could be achieved using microfluidics. Liver slices were viable for at least 24 h in the microdevice. The compound, 7‐ethoxycoumarin (7‐EC), was chosen to test metabolism, since its metabolism includes both phase I and phase II metabolism and when tested in the conventional well plate system, correlates well with the in vivo situation (De Kanter et al. 2004. Xenobiotica 34(3): 229–241.). The metabolic rate of 7‐EC was found to be 214 ± 5 pmol/min/mg protein in the microdevice, comparable to well plates, and was constant over time for at least 3 h. This perifusion system better mimics the in vivo situation, and has the potential to significantly contribute to drug metabolism and toxicology studies of novel chemical entities. Biotechnol. Bioeng. 2010;105: 184–194. © 2009 Wiley Periodicals, Inc.