Characterization of a microfluidics-based in vitro human-microbial crosstalk device
The human gastrointestinal (GI) tract has been linked to countless idiopathic diseases, such as type 1 diabetes, obesity, inflammatory bowel disease, colorectal cancer, and neurodegenerative diseases. A microfluidics-based in vitro co-culture model, developed at the Center for Applied NanoBioscience and Medicine (ANBM) at the University of Arizona, mimics an in vivo environment between human GI epithelial cells (Caco-2) and anaerobically grown Lactobacillus rhamnosus GG (LGG) cells to study human-host interactions with gastrointestinal microbiota. This human-microbial crosstalk (HuMiX) device is an advancement for in vitro models due to its modular architecture which provides access to individual co-cultured cell contingents. An improved device model was characterized by cell proliferation and tight-junction staining of Caco-2 cells, as compared to the previous device. Physicochemical parameters of the HuMiX device are controlled through continuous perfusion of culture media into each microchamber. Preparation of anoxic (<0.5%) media for the microbial microchamber was attempted through chemical sparging, where N2 gas was bubbled into the growth medium to remove dissolved oxygen. Preliminary results demonstrated that at a low flow rate (20 L/min) required by the HuMiX device, multiple factors such as tubing, connectors, peristaltic pumping, and unsuitable oxygen sensors influenced the ability to acquire anoxic media and appropriately measure the oxygen content.