# Linking E-Cigarette Aerosol Characteristics to Mechanisms of Pulmonary Toxicity

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2021 · $448,048

## Abstract

ABSTRACT Little is known regarding the physiochemical characteristics or health-related effects for the
large array of aerosols that are inhaled by electronic cigarette (e-cig) users. We have therefore assembled a
multidisciplinary team that combines expertise in aerosol sciences, in vitro high throughput screening (HTS),
live animal imaging, and inhalation toxicology in order to address these issues. Our primary objective is to un-
derstand how atomizer parameters and key ingredients in e-liquid, which are shared across different e-cig
brands, contribute to undesirable aerosol characteristics and pulmonary toxicity. Based on our in vitro and in
vivo preliminary data, the working hypotheses are (1) the heating coil temperature, chemical composition and
vapor pressure of the major ingredients in e-liquid can be linked in a predictive manner to e-cig aerosol charac-
teristics associated with toxicity; (2) a simulated lung exposure model employing air-liquid interface will provide
novel insight into the dilution and dispersion of aerosol components and their potential for epithelial toxicity;
and (3) correlations between HTS, aerosol composition, and endpoint toxicity measures will be validated when
animals are exposed to e-cig aerosols in vivo. Three specific aims are proposed: (1) To systematically vary e-
cig device parameters and e-liquid compositions to determine their impacts on aerosol physiochemical charac-
teristics and in vitro toxicity; (2) To expose airway epithelial cells to e-cig aerosols as would occur in the human
lung during vaping and determine toxicity signatures resulting from specific physiochemical features.; and (3)
To determine acute and sub-chronic lung toxicity profiles resulting from exposures to e-cig aerosols us-ing
transgenic animals. There are several novel aspects of this proposal that include: (1) a focus on key e-cig de-
sign features (coil composition, coil resistance, and applied voltage) and e-liquid components (propylene glycol
(PG), vegetable glycerin (VG), nicotine, and flavoring), that are shared across a wide range of brands, with a
goal of developing predictive assessments linking their impact on aerosol characteristics to specific toxicity; (2)
use of a mechanism-based HTS to systematically screen a large number of e-cig aerosols and identify those
with toxicity signals that warrant further investigation; (3) development of a ventilated artificial lung model em-
ploying primary human bronchial epithelial cells (HBEC)/air-liquid interface (ALI) cultures to carry out a detailed
assessment of human exposure and detect early signals of epithelial toxicity; and (4) focused validation studies
using transgenic mice and live animal imaging to assess the toxicity of acute and repeated exposure on the
lung in vivo. This proposed research is significant in that it will identify key e-cig design parameters and e-liquid
ingredients that can be readily assessed by HTS yet are linked in a predictive manner to more detail...

## Key facts

- **NIH application ID:** 10245161
- **Project number:** 5R01HL139379-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** YIFANG ZHU
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $448,048
- **Award type:** 5
- **Project period:** 2018-09-14 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10245161

## Citation

> US National Institutes of Health, RePORTER application 10245161, Linking E-Cigarette Aerosol Characteristics to Mechanisms of Pulmonary Toxicity (5R01HL139379-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10245161. Licensed CC0.

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