Chemical Analysis of Deep-Lung Fluid Derived from Exhaled Breath Particles

Area of Science:

• Pulmonary medicine
• Analytical chemistry
• Biomarker discovery

Background:

• Breath particles offer non-invasive access to peripheral airway lining fluid for biomarker analysis.
• Traditional breath condensate methods suffer from contamination and dilution, limiting quantitative accuracy.
• Existing methods struggle with variable particle production and subject differences.

Purpose of the Study:

• To develop a novel method for capturing, drying, and chemically analyzing breath particles for quantitative biomarker discovery.
• To overcome limitations of traditional breath condensate collection, including contamination and dilution.
• To enable non-invasive analysis of lung fluid biomarkers.

Main Methods:

• A flexible chamber captures and dries breath particles, decoupling breathing and sampling airflows.
• Optical particle characterization is performed during collection for accurate analysis.
• An impactor sampler collects particles in a microreactor for downstream mass spectrometry analysis.

Main Results:

• Nuclear Magnetic Resonance (NMR) spectroscopy measured high sodium (Na) and phosphocholine lipid concentrations in dried breath particles.
• Dehydration of particles was estimated to reduce volume by approximately 5.5-fold.
• Quantification of urea in breath particles demonstrated consistency with blood plasma values, validating the method.

Conclusions:

• The developed method enables accurate, non-invasive analysis of lung fluid biomarkers from breath particles.
• Decoupling breath collection and aerosol capture enhances sample quality and analytical precision.
• This technique holds promise for advancing non-invasive diagnostics and understanding lung physiology.