Imaging Particle Deposition Airway-by-Airway in Laboratory Animals

The deposition locations of inhaled particles play a critical role in determining the subsequent health effects elicited. Cell type and distribution within the lung varies both by region and from airway to airway, making precise knowledge of particle locations an important factor in determining toxicity of harmful particles as well as benefits of therapeutic ones. Administering therapeutic drugs by inhalation offers advantages such as avoidance of first pass metabolism for oral drugs, faster absorption, low cost, needle avoidance and patient convenience. Knowledge of where particles have deposited is an important factor in understanding the effects of this type of drug administration and may enable more effective targeting of specific sites within the lung. Similarly, such knowledge also aids studies of harmful effects from exposure to suspended particles through occupational exposure, air pollution, or smoke.;Mathematical models are often employed in place of empirical exposure methods to predict deposition locations and patterns. These models can provide valuable insight without the requirement of actual exposure and subsequent particle detection, but must be validated against empirical data to ensure accurate predictions. There are few methods for identifying the exact pattern of deposition once the drug or particle enters the airways. Here we present a newly developed method for simultaneously imaging airways and deposited particles in three dimensions with high spatial resolution.