Intubation-mediated intratracheal (IMIT) instillation: a noninvasive, lung-specific delivery system

Area of Science:

• Pulmonary Medicine
• Animal Models
• Respiratory Physiology

Background:

• Murine models are crucial for respiratory disease research.
• Significant physiological differences exist between murine and human upper respiratory tracts (URT).
• Intranasal instillation in mice can confound lower respiratory tract (LRT) disease studies due to URT variations.

Purpose of the Study:

• To develop a novel technique for direct lung-specific delivery in mice.
• To overcome limitations of intranasal instillation in murine respiratory disease models.
• To improve the accuracy and reproducibility of delivering agents to the mouse lung.

Main Methods:

• Intubation-mediated intratracheal (IMIT) instillation, a noninvasive two-step process.
• Initial intubation of mice with verification of tracheal catheter placement.
• Direct delivery of bacterial agents into the lungs via a blunt needle inserted into the catheter.

Main Results:

• Achieved >98% efficacy for delivery directly into the lungs.
• Demonstrated excellent distribution of the instilled reagent throughout the lung.
• Minimized risk of bloodstream or digestive tract contamination compared to surgical methods.

Conclusions:

• IMIT instillation is a novel, accurate, and reproducible method for studying LRT diseases in mice.
• This technique enhances the utility of mice as surrogates for human respiratory disease research.
• The IMIT method is suitable for Good Laboratory Practice Standards (GLPS) and delivery of various reagents to the lung.