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bioRxiv · 10.1101/2020.05.22.111096

A Novel Standalone Microfluidic Device for Local Control of Oxygen Tension for Intestinal-Bacteria Interactions

Wang, C.·Dang, T.·Baste, J.·Joshi, A. A.·Bhushan, A.
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Abstract

The intestinal environment is unique because it supports the intestinal epithelial cells under a normal oxygen environment and the microbiota under an anoxic environment. Due to importance of understanding the interactions between the epithelium and the microbiota, there is a strong need for developing representative and simple experimental models. Current approaches do not capture the dual-oxygen environment, require external anaerobic chambers, or are complex. Another major limitation is that in the solutions that can mimic the dual-oxygen environment, the oxygenation level of the epithelial cells is not known, raising the question whether the cells are hypoxic. We report standalone microfluidic devices that form a dual-oxygen environment without the use of an external anaerobic chamber or oxygen scavengers to coculture intestinal epithelial and bacterial cells. By changing the thickness of the device cover, the oxygen tension in the chamber could be modulated. We verified the oxygen levels using several tests: microscale oxygen sensitive sensors incorporated within the devices, hypoxic immunostaining of Caco-2 cells, and genetically encoded bacteria. Collectively, these methods monitored oxygen concentrations in devices more comprehensively than previous reports and allowed for control of oxygen tension to match the requirements of both intestinal cells and anaerobic bacteria. Our experimental model is supported by the mathematical model that considers diffusion of oxygen into the top chamber and the cellular oxygen consumption rate. This allowed us to experimentally determine the oxygen consumption rate of the epithelial cells more precisely.

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Wang, C., Dang, T., Baste, J., Joshi, A. A., Bhushan, A.. 2020-05-26. A Novel Standalone Microfluidic Device for Local Control of Oxygen Tension for Intestinal-Bacteria Interactions. https://doi.org/10.1101/2020.05.22.111096

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