A microfluidic in vitro system for the quantitative study of the stomach mucus barrier function

Area of Science:

• Biophysics
• Gastroenterology
• Biomaterials Science

Background:

• The stomach lining is protected from digestive acids by a gastric mucus layer.
• The precise biophysical mechanisms of this protective acid barrier remain poorly understood.
• Understanding this barrier is crucial for treating acid-related gastrointestinal disorders.

Purpose of the Study:

• To develop and utilize an in vitro microfluidic tool to investigate the stomach acid barrier.
• To characterize the role of mucin polymers in hindering acid diffusion.
• To provide a platform for studying mucus barrier functions and drug interactions.

Main Methods:

• Developed a microfluidic device simulating in vivo gastric mucus secretion.
• Reconstituted the hydrogen ion (H+) concentration gradient and outward flow characteristic of the stomach lumen.
• Used purified mucin polymers to mimic mucus secretion against an acidic zone on the chip.

Main Results:

• Demonstrated that a continuously secreted mucin layer effectively hinders acid diffusion.
• Provided quantitative insights into the barrier properties of mucins against acid.
• Validated the microfluidic system's ability to mimic physiological conditions.

Conclusions:

• Continuously secreted mucins play a significant role in the stomach's acid barrier function.
• The developed microfluidic tool offers a novel platform for studying mucus barrier mechanisms.
• This system has potential applications in evaluating mucus-drug interactions and developing new therapies.