Integrated Gut and Liver Microphysiological Systems for Quantitative In Vitro Pharmacokinetic Studies

Abstract

Abstract.Investigation of the pharmacokinetics (PK) of a compound is of significant importance during the early stages of drug development, and therefore several in vitro systems are routinely employed for this purpose. However, the need for more physiologically realistic in vitro models has recently fueled the emerging field of tissue-engineered 3D cultures, also referred to as organs-on-chips, or microphysiological systems (MPSs). We have developed a novel fluidic platform that interconnects multiple MPSs, allowing PK studies in multi-organ in vitro systems along with the collection of high-content quantitative data. This platform was employed here to integrate a gut and a liver MPS together in continuous communication, and investigate simultaneously different PK processes taking place after oral drug administration in humans (e.g., intestinal permeability, hepatic metabolism). Measurement of tissue-specific phenotypic metrics indicated that gut and liver MPSs can be fluidically coupled with circulating common medium without compromising their functionality. The PK of diclofenac and hydrocortisone was investigated under different experimental perturbations, and results illustrate the robustness of this integrated system for quantitative PK studies. Mechanistic model-based analysis of the obtained data allowed the derivation of the intrinsic parameters (e.g., permeability, metabolic clearance) associated with the PK processes taking place in each MPS. Although these processes were not substantially affected by the gut-liver interaction, our results indicate that inter-MPS communication can have a modulating effect (hepatic metabolism upregulation). We envision that our integrative approach, which combines multi-cellular tissue models, multi-MPS platforms, and quantitative mechanistic modeling, will have broad applicability in pre-clinical drug development.

Gut-Liver physiomimetics reveal paradoxical modulation of IBD-related inflammation by short-chain fatty acids

“…We focused initial experiments on behaviors of the gut-liver axis in the absence and presence of SCFA without adaptive immune cells, using the gut and liver MPSs connected at recirculating flow rates of 30 ml/day. Integration of gut and liver MPSs significantly affects their individual phenotypes and gene expression ( Fig.S4A,B) in accordance with our previous observations during interaction of a CaCo-2 cell based MPS with the liver MPS (30,31). The most notable effects were decreased glycolysis and increased CYP450 and steroid hormone synthesis of the gut MPS ( Fig.S4A) and increased CYP450 activity with downregulation of inflammatory pathways in the liver MPSs (Fig.S4B).…”

“…Gut MPSs were established by seeding equal numbers of epithelial cells from a UC donor and from a non-diseased control on separate transwell membranes, and then attaching peripheral blood mononuclear cells (PBMC)-derived macrophages and dendritic cells on the basolateral side of the membrane after monolayer differentiation. All experiments were conducted in a slight modification of culture medium which had previously been tailored for physiological inflammatory responses of the human liver MPS, in which the extreme supraphysiological concentrations of cortisol and insulin typically used to maintain CYP450 levels in primary hepatocyte cultures were reduced to concentrations within the physiological range (30).…”

“…MPSs are in vitro models that are both complex -comprising multiple cell types, specialized microenvironments, and perfusion -and yet reductionist, as they capture only the most salient features of in vivo organ behavior required to model the physiological process in question. We previously developed a physiomimetic platform technology that supports long-term (weeks) integrated co-culture of up to 10 fluidically-communicating MPSs, featuring individuallyaddressable on-board microfluidic pumps compatible with highly lipophilic compounds such as steroid hormones (29)(30)(31). Here, we use a new iteration of the platform designed to model the gut-liver-immune axis by connecting a gut MPS of UC (primary human UC epithelium, dendritic cells and macrophages) with a liver MPS (healthy human hepatocytes and Kupffer cells) and circulating Treg/Th17 cells.…”

C. difficile-associated antibiotics prime the host for infection by a microbiome-independent mechanism

“…To test the commensal-independent effects of antibiotics on the host, we used a transwell-based in vitro epithelial barrier without bacteria to model a germ-free human gut 21,22 . We treated mature mucosal barriers with antibiotics with CDAD odds ratios, from one (no risk) to 17 (highest risk; Supplemental Table 1) in order to achieve complete coverage of the CDAD risk landscape.…”

Mucus models to evaluate the diffusion of drugs and particles

“…In another system, human liver (i.e. human primary hepatocytes and Kupffer cells) and intestinal (C2BBe1 Caco-2 clone, HT29-MTX, and human primary dendritic cells) modules were used to study gut-liver interaction for 2 weeks[115, 116]. Endotoxemia, a condition characterized by the presence of circulating lipopolysaccharide (LPS), was simulated by the addition of 2 ng/mL LPS into the circulating media.…”