Sandwich-Cultured Hepatocytes for Mechanistic Understanding of Hepatic Disposition of Parent Drugs and Metabolites by Transporter–Enzyme Interplay

Abstract

Functional interplay between transporters and drug-metabolizing enzymes is currently one of the hottest topics in the field of drug metabolism and pharmacokinetics. Uptake transporter-enzyme interplay is important to determine intrinsic hepatic clearance based on the extended clearance concept. Enzyme and efflux transporter interplay, which includes both sinusoidal (basolateral) and canalicular efflux transporters, determines the fate of metabolites formed in the liver. As sandwich-cultured hepatocytes (SCHs) maintain metabolic activities and form a canalicular network, the whole interplay between uptake and efflux transporters and drug-metabolizing enzymes can be investigated simultaneously. In this article, we review the utility and applicability of SCHs for mechanistic understanding of hepatic disposition of both parent drugs and metabolites. In addition, the utility of SCHs for mimicking species-specific disposition of parent drugs and metabolites in vivo is described. We also review application of SCHs for clinically relevant prediction of drug-drug interactions caused by drugs and metabolites. The usefulness of mathematical modeling of hepatic disposition of parent drugs and metabolites in SCHs is described to allow a quantitative understanding of an event in vitro and to develop a more advanced model to predict in vivo disposition.

Clearance in Drug Design

“…The validation of in vitro assays for predicting hepatic uptake limited clearance has been limited by the relative paucity of compounds for which hepatic uptake is proven to be the rate-determining step in human clearance. Hepatocytes can be grown in culture under conditions where they will express drug uptake transporters and potential form bile ducts (e.g., plated hepatocytes or sandwich culture hepatocytes). − The intrinsic clearance values determined for uptake substrates tend to be much lower than would be required to explain the hepatic clearance of these compounds in vivo (for the few compounds where the full data set is available). , Thus, extensive empirical scaling factors are currently required for prospective human clearance prediction. , On a mechanistic level, the interplay between metabolism and transport is captured by what is called the extended clearance concept. This concept expands the hepatic CL int,u parameter into its component parts to provide a better understanding of the rate determining mechanisms of clearance (eq , which assumes all parameters represent the unbound values for the sake of simplicity).…”

Bioprinting of Multiscaled Hepatic Lobules within a Highly Vascularized Construct

“…However, despite hepatocytes comprising 80% of the total liver volume, primary hepatocyte cultivation is still difficult under 2D conditions. [ 30,31 ] To overcome this, 3D hepatocyte spheroid [ 32,33 ] or 2D sandwich culture [ 34,35 ] methods have been utilized for hepatotoxicity testing. A recent study proved that 3D hepatocyte spheroids were more functionally stable and exhibited increased sensitivity after long‐term repeated exposures.…”

Evaluation of Erythromycin as a Tool to Assess CYP3A Contribution of Low Clearance Compounds in a Long-Term Hepatocyte Culture

“…The use of suspension hepatocytes for the conduct of CYP450 reaction phenotyping studies has been considered advantageous over the use of recombinant enzymes or microsomes, as hepatocytes in suspension generally yield greater compound turnover (through extended incubation times) and possess the complete array of hepatic drug metabolizing enzymes (Argikar et al, 2016;Matsunaga et al, 2018). However, suspension hepatocytes are limited by the relatively short lifespan, i.e., they can only be used for a maximum of 4-6 hours (Gebhardt et al, 2003;Chan et al, 2013).…”