An in vitro intestinal platform with a self-sustaining oxygen gradient to study the human gut/microbiome interface

Abstract

An oxygen gradient formed along the length of colonic crypts supports stem-cell proliferation at the normoxic crypt base while supporting obligate anaerobe growth in the anoxic colonic lumen. Primary human colonic epithelial cells derived from human gastrointestinal stem cells were cultured within a device possessing materials of tailored oxygen permeability to produce an oxygen-depleted luminal (0.8% ± 0.1% O2) and oxygen-rich basal (11.1% ± 0.5% O2) compartment. This oxygen difference created a stable oxygen gradient across the colonic epithelial cells which remained viable and properly polarized. Facultative and obligate anaerobes Lactobacillus rhamnosus, Bifidobacterium adolescentis, and Clostridium difficile grew readily within the luminal compartment. When formed along the length of an in vitro crypt, the oxygen gradient facilitated cell compartmentalization within the crypt by enhancing confinement of the proliferative cells to the crypt base. This platform provides a simple system to create a physiological oxygen gradient across an intestinal mimic while simultaneously supporting anaerobe co-culture.

Magnetically-Propelled Fecal Surrogates for Modeling the Impact of Solid-Induced Shear Forces on Primary Colonic Epithelial Cells

“…In summary, the platform developed in this report represents an ideal method for examining the broad scope of effects that accompany direct mechanical stimulation as it utilizes primary human cells, enables programmable alterations of colonic motility, and can be readily adapted by others. The results of any future mechanotransduction studies will undoubtedly be bolstered by the inclusion of other critical components of intestinal tissue, including the microbiome, immune cells, and fibroblasts, which will present their own mechanosensitive reactions [82, 83].…”

Microbiota‐Host Immunity Communication in Neurodegenerative Disorders: Bioengineering Challenges for In Vitro Modeling

“…[ 131 ] In vitro modeling of this interface is consolidated in the literature. There are several examples of engineered OOCs, commonly known as gut‐on‐chips (GOCs), [ 132–134 ] which successfully incorporate physiologically relevant features, such as the flow of bacterial molecules, microbial co‐culture in an anoxic–oxic interface (AOI), [ 135 ] a robust mucus bi‐layer with physiological thickness, or physical deformations for peristalsis‐like motion. [ 17 ] However, in the perspective of immune response modeling, most of today's in vitro gut models lack tissue‐resident immune cells.…”

Biomimetic Gut Model Systems for Development of Targeted Microbial Solutions for Enhancing Warfighter Health and Performance

“…One technique employs biofabricated supports to recreate the structure of intestinal villi and crypts, which when seeded with epithelial cells present improved cellular physiology and differentiation (59,60); others use a porous silk protein scaffolding system to construct a 3D tubular architecture representation of the intestines (61,62). The oxygen gradient device mimics the topology of colonic crypts using collagen scaffolds for supporting the physical interaction of human primary colon epithelial stem cells and obligate anaerobes Bifidobacterium adolescentis and Clostridium difficile for up to 24 h through the generation of a self-sustaining, stable oxygen gradient across 3D crypt topology (63). The device employs an oxygen-impermeable plug creating an anaerobic environment by minimizing oxygen influx from above a monolayer of respiring epithelial cells separating apical anaerobic and basal aerobic compartments.…”