Innovative microfluidic model for investigating the intestinal mucus barrier: numerical and experimental perspectives

Area of Science:

• Biophysics
• Gastroenterology
• Biomaterials Science

Background:

• The intestinal mucus layer is a crucial barrier against pathogens and for regulating absorption.
• Previous studies focused on static mucus, neglecting the impact of luminal flow and shear stress.
• Understanding mucus dynamics under flow is vital for drug delivery and disease research.

Purpose of the Study:

• To develop and validate a microfluidic platform simulating intestinal mucus-flow interactions.
• To quantify particle penetration and mucus dislodgement rates under varying viscosity conditions.
• To correlate microfluidic observations with rheological properties and numerical simulations.

Main Methods:

• Utilized a microfluidic device with biosimilar mucus models (BSM) of varying viscosity and Hank's Balanced Salt Solution (HBSS) as luminal fluid.
• Employed particle tracking velocimetry to analyze fluid dynamics and measure particle penetration and mucus dislodgement.
• Performed rheological tests, physicochemical characterizations, and numerical simulations using COMSOL Multiphysics.

Main Results:

• Demonstrated significant differences in particle penetration and mucus dislodgement between low-viscosity (BSM-1) and high-viscosity (BSM-2) mucus models.
• Observed that mucus viscosity, governed by rheological properties, directly influences shear-induced dislodgement and particle transport.
• Validated microfluidic experimental results with COMSOL Multiphysics simulations.

Conclusions:

• The microfluidic platform effectively models intestinal mucus barrier function under dynamic flow conditions.
• Mucus viscosity is a key determinant of its barrier integrity and susceptibility to dislodgement by luminal flow.
• This approach provides a foundation for future research on intestinal barrier dynamics and therapeutic interventions.