Exposure to Aged Vaping Emissions at an Air-Liquid Interface: Potential for Disruption of the Respiratory Epithelial Barrier

WONSIK WOO, Linhui Tian, Ying-Hsuan Lin, University of California, Riverside

     Abstract Number: 119
     Working Group: Health-Related Aerosols

Abstract
Vaping indoors has brought up concerns regarding its effects on indoor air quality due to the release of massive amounts of aerosol during a typical session. Once in the air, these vaping emissions are subjected to aging processes that are governed by ambient oxidants and gas-particle partitioning processes. Recent work has shown that e-cigarette aerosols can be effectively aged by ambient levels of ozone (O3), forming reactive oxygen species (ROS) and carbonyls that are enriched within the aged aerosols. The toxicity associated with second-hand exposure to these aged aerosols has not been fully explored, but there is an expectation that these aged emissions pose a greater risk to pulmonary health compared to their fresh counterparts. In this study, our goal is to model this process of second-hand exposure by utilizing human bronchial epithelial cells that are grown at an air-liquid interface (ALI) and undergo exposures with an in vitro aerosol exposure system (VITROCELL® 6/4 CF). E-cigarette aerosols will undergo aging in a 0.5 m3 FEP chamber by reactions with O3. The chamber will be connected to the exposure system, where NHBE cells will be exposed to both fresh and aged vaping emissions. Differential effects that influence the integrity of the respiratory epithelium from fresh and aged exposures will be determined by measuring differences in transepithelial electrical resistance (TEER) as well as lactate dehydrogenase (LDH) release. Furthermore, gene expression analysis with RNA-Seq and changes in cellular lipid profiles with LC-MS/MS will provide insight about the cellular mechanisms that mediate the toxicity of our aged e-cigarette aerosols. Since the aging process of e-cigarette aerosols will induce the formation of potentially toxic compounds, we expect to see significant differences in the toxicological endpoints and biomarkers that indicate the ability of aged e-cigarette aerosols to reduce the integrity of the respiratory epithelium.