Multimodal Diagnostics of Changes in Rat Lungs after Vaping.

Area of Science:

• Pulmonary Medicine
• Biophysics
• Toxicology

Background:

• Electronic cigarette use is prevalent, with e-liquids potentially causing lung tissue changes impacting gas exchange.
• While less severe than traditional smoking, e-cigarette vaping can induce morphological alterations in lung tissue.

Purpose of the Study:

• To investigate the morphological and optical property changes in lung tissue due to e-liquid aerosol exposure.
• To model passive exposure to e-liquid aerosols (glycerol/propylene glycol mixture) in Wistar rats.

Main Methods:

• Ex vivo and in vivo studies using Wistar rats exposed to e-liquid or its aerosol.
• Evaluation of lung tissue using optical coherence tomography (OCT), spectrometry, and histological analysis (hematoxylin and eosin staining).
• Quantification of absorption and reduced scattering coefficients and assessment of tissue morphology.

Main Results:

• E-liquid exposure, both ex vivo and via aerosol, led to optical clearing of lung tissue.
• Histological findings included alveolar emphysema, thickened septa, and plasma permeation, more pronounced in ex vivo exposure.
• OCT imaging resolution and contrast were improved by e-liquid aerosol exposure.
• Spectral analysis indicated lung tissue dehydration, attributed to the hyperosmotic nature of glycerol and propylene glycol.

Conclusions:

• Vaping e-liquids reduces lung tissue air volume and increases structural density.
• These changes enhance OCT image contrast compared to intact lung tissue.
• E-liquid aerosol exposure can lead to dehydration and pathological changes in lung tissue.