Multimodal Diagnostics of Changes in Rat Lungs after Vaping

Irina Yu Yanina; Vadim D Genin; Elina A Genina; Dmitry A Mudrak; Nikita A Navolokin; Alla B Bucharskaya; Yury V Kistenev; Valery V Tuchin

doi:10.3390/diagnostics13213340

Multimodal Diagnostics of Changes in Rat Lungs after Vaping

Diagnostics (Basel). 2023 Oct 30;13(21):3340. doi: 10.3390/diagnostics13213340.

Authors

Irina Yu Yanina^{1

2}, Vadim D Genin^{1

2

3}, Elina A Genina^{1

2

3}, Dmitry A Mudrak⁴, Nikita A Navolokin^{4

5

6}, Alla B Bucharskaya^{2

3

4}, Yury V Kistenev², Valery V Tuchin^{1

2

3

7}

Affiliations

¹ Institution of Physics, Saratov State University, 410012 Saratov, Russia.
² Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia.
³ Science Medical Center, Saratov State University, 410012 Saratov, Russia.
⁴ Department of Pathological Anatomy, Saratov State Medical University, 410012 Saratov, Russia.
⁵ Experimental Department, Center for Collective Use of Experimental Oncology, Saratov State Medical University, 410012 Saratov, Russia.
⁶ State Healthcare Institution, Saratov City Clinical Hospital No. 1 Named after Yu.Ya. Gordeev, 410017 Saratov, Russia.
⁷ Institute of Precision Mechanics and Control, FRC "Saratov Scientific Centre of the Russian Academy of Sciences", 410028 Saratov, Russia.

Abstract

(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to traditional cigarette smoking. Nevertheless, e-liquid vaping can cause morphological changes in lung tissue, which affects and impairs gas exchange. This work studied the changes in morphological and optical properties of lung tissue under the action of an e-liquid aerosol. To do this, we implemented the "passive smoking" model and created the specified concentration of aerosol of the glycerol/propylene glycol mixture in the chamber with the animal. (2) Methods: In ex vivo studies, the lungs of Wistar rats are placed in the e-liquid for 1 h. For in vivo studies, Wistar rats were exposed to the e-liquid vapor in an aerosol administration chamber. After that, lung tissue samples were examined ex vivo using optical coherence tomography (OCT) and spectrometry with an integrating sphere. Absorption and reduced scattering coefficients were estimated for the control and experimental groups. Histological sections were made according to the standard protocol, followed by hematoxylin and eosin staining. (3) Results: Exposure to e-liquid in ex vivo and aerosol in in vivo studies was found to result in the optical clearing of lung tissue. Histological examination of the lung samples showed areas of emphysematous expansion of the alveoli, thickening of the alveolar septa, and the phenomenon of plasma permeation, which is less pronounced in in vivo studies than for the exposure of e-liquid ex vivo. E-liquid aerosol application allows for an increased resolution and improved imaging of lung tissues using OCT. Spectral studies showed significant differences between the control group and the ex vivo group in the spectral range of water absorption. It can be associated with dehydration of lung tissue owing to the hyperosmotic properties of glycerol and propylene glycol, which are the main components of e-liquids. (4) Conclusions: A decrease in the volume of air in lung tissue and higher packing of its structure under e-liquid vaping causes a better contrast of OCT images compared to intact lung tissue.

Keywords: OCT; histology; lung; optical properties; vape.

Grants and funding

220/Decree of the Government of the Russian Federation