Publications

@article{abbas_primary_2025,

title = {A primary human Gut/Liver microphysiological system to estimate human oral bioavailability},

author = {Yassen Abbas and Morné van Wyk and Hailey Sze and James Christophi and Ashley A. Spreen and Robert Jarrett Bliton and Elizabeth M. Boazak and Tomasz Kostrzewski},

url = {https://dmd.aspetjournals.org/article/S0090-9556(25)09139-1/fulltext},

doi = {10.1016/j.dmd.2025.100130},

issn = {0090-9556, 1521-009X},

year  = {2025},

date = {2025-09-01},

urldate = {2025-09-01},

journal = {Drug Metabolism and Disposition},

volume = {53},

number = {9},

note = {Publisher: Elsevier},

keywords = {absorption, Bioavailability, Biopharmaceutics Classification System, Fa, Fg, Gut liver microphysiological system, metabolism, microphysiological system, Organ-on-a-chip, Papp, pharmacokinetic},

pubstate = {published},

tppubtype = {article}

}

@article{sharma_developing_2024,

title = {Developing an adult stem cell derived microphysiological intestinal system for predicting oral prodrug bioconversion and permeability in humans},

author = {Abhinav Sharma and Liang Jin and Xue Wang and Yue-Ting Wang and David M. Stresser},

url = {https://pubs.rsc.org/en/content/articlelanding/2024/lc/d3lc00843f},

doi = {10.1039/D3LC00843F},

issn = {1473-0189},

year  = {2024},

date = {2024-01-17},

urldate = {2024-01-17},

journal = {Lab Chip},

volume = {24},

number = {2},

pages = {339–355},

abstract = {Microphysiological systems (MPS) incorporating human intestinal organoids have shown the potential to faithfully model intestinal biology with the promise to accelerate development of oral prodrugs. We hypothesized that an MPS model incorporating flow, shear stress, and vasculature could provide more reliable measures of prodrug bioconversion and permeability. Following construction of jejunal and duodenal organoid MPS derived from 3 donors, we determined the area under the concentration–time (AUC) curve for the active drug in the vascular channel and characterized the enzymology of prodrug bioconversion. Fosamprenavir underwent phosphatase mediated hydrolysis to amprenavir while dabigatran etexilate (DABE) exhibited proper CES2- and, as anticipated, not CES1-mediated de-esterification, followed by permeation of amprenavir to the vascular channel. When experiments were conducted in the presence of bio-converting enzyme inhibitors (orthovanadate for alkaline phosphatase; bis(p-nitrophenyl)phosphate for carboxylesterase), the AUC of the active drug decreased accordingly in the vascular channel. In addition to functional analysis, the MPS was characterized through imaging and proteomic analysis. Imaging revealed proper expression and localization of epithelial, endothelial, tight junction and catalytic enzyme markers. Global proteomic analysis was used to analyze the MPS model and 3 comparator sources: an organoid-based transwell model (which was also evaluated for function), Matrigel embedded organoids and finally jejunal and duodenal cadaver tissues collected from 3 donors. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) of global proteomic data demonstrated that all organoid-based models exhibited strong similarity and were distinct from tissues. Intestinal organoids in the MPS model exhibited strong similarity to human tissue for key epithelial markers via HCA. Quantitative proteomic analysis showed higher expression of key prodrug converting and drug metabolizing enzymes in MPS-derived organoids compared to tissues, organoids in Matrigel, and organoids on transwells. When comparing organoids from MPS and transwells, expression of intestinal alkaline phosphatase (ALPI), carboxylesterase (CES)2, cytochrome P450 3A4 (CYP3A4) and sucrase isomaltase (SI) was 2.97-, 1.2-, 11.3-, and 27.7-fold higher for duodenum and 7.7-, 4.6-, 18.1-, and 112.2-fold higher for jejunum organoids in MPS, respectively. The MPS approach can provide a more physiological system than enzymes, organoids, and organoids on transwells for pharmacokinetic analysis of prodrugs that account for 10% of all commercial medicines.},

note = {Publisher: The Royal Society of Chemistry},

keywords = {absorption, Bioavailability, Biological Transport, Caco-2 Cells, drug absorption, drug metabolising enzymes ({DME}), drug permeability, intestinal barrier, oral bioavailability, permeability},

pubstate = {published},

tppubtype = {article}

}

@article{speer_evaluation_2019,

title = {Evaluation of human primary intestinal monolayers for drug metabolizing capabilities},

author = {Jennifer E. Speer and Yuli Wang and John K. Fallon and Philip C. Smith and Nancy L. Allbritton},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829970/},

doi = {10.1186/s13036-019-0212-1},

issn = {1754-1611},

year  = {2019},

date = {2019-11-04},

urldate = {2019-11-04},

journal = {J. Biol. Eng},

volume = {13},

pages = {82},

abstract = {Background 

The intestinal epithelium is a major site of drug metabolism in the human body, possessing enterocytes that house brush border enzymes and phase I and II drug metabolizing enzymes (DMEs). The enterocytes are supported by a porous extracellular matrix (ECM) that enables proper cell adhesion and function of brush border enzymes, such as alkaline phosphatase (ALP) and alanyl aminopeptidase (AAP), phase I DMEs that convert a parent drug to a more polar metabolite by introducing or unmasking a functional group, and phase II DMEs that form a covalent conjugate between a functional group on the parent compound or sequential metabolism of phase I metabolite. In our effort to develop an in vitro intestinal epithelium model, we investigate the impact of two previously described simple and customizable scaffolding systems, a gradient cross-linked scaffold and a conventional scaffold, on the ability of intestinal epithelial cells to produce drug metabolizing proteins as well as to metabolize exogenously added compounds. While the scaffolding systems possess a range of differences, they are most distinguished by their stiffness with the gradient cross-linked scaffold possessing a stiffness similar to that found in the in vivo intestine, while the conventional scaffold possesses a stiffness several orders of magnitude greater than that found in vivo. 

Results 

The monolayers on the gradient cross-linked scaffold expressed CYP3A4, UGTs 2B17, 1A1 and 1A10, and CES2 proteins at a level similar to that in fresh crypts/villi. The monolayers on the conventional scaffold expressed similar levels of CYP3A4 and UGTs 1A1 and 1A10 DMEs to that found in fresh crypts/villi but significantly decreased expression of UGT2B17 and CES2 proteins. The activity of CYP3A4 and UGTs 1A1 and 1A10 was inducible in cells on the gradient cross-linked scaffold when the cells were treated with known inducers, whereas the CYP3A4 and UGT activities were not inducible in cells grown on the conventional scaffold. Both monolayers demonstrate esterase activity but the activity measured in cells on the conventional scaffold could not be inhibited with a known CES2 inhibitor. Both monolayer culture systems displayed similar ALP and AAP brush border enzyme activity. When cells on the conventional scaffold were incubated with a yes-associated protein (YAP) inhibitor, CYP3A4 activity was greatly enhanced suggesting that mechano-transduction signaling can modulate drug metabolizing enzymes. 

Conclusions 

The use of a cross-linked hydrogel scaffold for expansion and differentiation of primary human intestinal stem cells dramatically impacts the induction of CYP3A4 and maintenance of UGT and CES drug metabolizing enzymes in vitro making this a superior substrate for enterocyte culture in DME studies. This work highlights the influence of mechanical properties of the culture substrate on protein expression and the activity of drug metabolizing enzymes as a critical factor in developing accurate assay protocols for pharmacokinetic studies using primary intestinal cells. 

Graphical abstract},

keywords = {Absorptive Enterocyte Monolayers, Bioavailability, drug metabolising enzymes ({DME}), epithelial barrier, Fg, Intestinal Epithelial Cells, permeability},

pubstate = {published},

tppubtype = {article}

}