A method for quantifying particle absorption from the small intestine of the mouse

Area of Science:

• Immunology and Microbiology
• Gastroenterology
• Nanotechnology

Background:

• Understanding particle absorption in the gastrointestinal tract is crucial for drug delivery and toxicology.
• Quantifying the translocation of orally administered substances, especially nanoparticles, into systemic circulation and lymphoid tissues requires sensitive methodologies.
• Peyer's patches and mesenteric lymph nodes are key sites for immune surveillance and potential entry points for absorbed materials.

Purpose of the Study:

• To develop and validate a novel method for quantifying the absorption and tissue distribution of fluorescent latex particles in the mouse small intestine.
• To assess particle uptake into Peyer's patches, mesenteric lymph nodes, and spleen following oral administration.
• To investigate factors influencing particle absorption, including dose, size, and animal's fed state.

Main Methods:

• Oral gavage of mice with fluorescent polystyrene latex particles.
• Collection of Peyer's patches, intestinal tissue, mesenteric lymph nodes, and spleen at various time points.
• Tissue solubilization using potassium hydroxide and surfactant, followed by particle quantification via flow cytometry.

Main Results:

• The developed method successfully detected and quantified low numbers of absorbed particles.
• The technique allowed for the measurement of particle uptake kinetics and clearance rates.
• Particle absorption was found to be dependent on particle dose, particle size, and the fed state of the animals.

Conclusions:

• A sensitive and exhaustive method for quantifying oral particle absorption and tissue distribution in mice has been established.
• The findings highlight the influence of particle characteristics and physiological conditions on gastrointestinal absorption.
• This methodology provides a valuable tool for research in oral drug delivery, nanoparticle safety, and gut-associated immunology.