Generating an In Vitro Gut Model with Physiologically Relevant Biophysical Mucus Properties

Area of Science:

• Biomedical Engineering
• Gastroenterology
• Materials Science

Background:

• In vitro gastrointestinal (GI) models are crucial for studying drug absorption, GI diseases, and drug delivery systems.
• A complete GI model requires both mucus and epithelial components, as mucus is vital for protection, barrier function, and microbiome support.
• The biophysical properties of mucus, such as viscosity and pore size, are critical for its function.

Purpose of the Study:

• To develop and characterize in vitro GI models using cocultures of Caco-2 enterocyte-like cells and HT29-MTX goblet-like cells.
• To determine the impact of coculture and mucus layer on epithelial permeability and mucus biophysical properties using multiple particle tracking (MPT).

Main Methods:

• Generated in vitro GI models using cocultures of Caco-2 and HT29-MTX cells.
• Utilized multiple particle tracking (MPT) to measure mucus pore size and microviscosity.
• Compared in vitro mucus properties to ex vivo mucus samples from mice and pigs.

Main Results:

• Increased HT29-MTX cell ratios led to greater mucus height, pore size, and microviscosity.
• A 90:10 Caco-2:HT29-MTX coculture exhibited mucus pore size similar to porcine jejunum.
• Mucus from 90:10 and 80:20 cocultures showed mechanical properties comparable to porcine jejunum and ileum mucus.

Conclusions:

• GI coculture models effectively simulate the mucus barrier.
• These models are valuable for applications in GI disease research, food absorption studies, and therapeutic development.