Exposure to aerosol of an e-vapor device with MESH™ technology had a lower biological impact than exposure to cigarette smoke on human bronchial and alveolar culture models: an in vitro systems toxicology assessment.

The harmful effects of cigarette smoke exposure on the respiratory tract are widely known. Exposure to aerosol from electronic vapor (e-vapor) products has been suggested to result in less risk of harm to smokers than CS exposure. Many studies have assessed the potential toxicity of the aerosol from e-vapor products in vitro. However, most studies have only tested the effects of liquid formulations applied directly to cell cultures but not those of the aerosolized formulations. In this study, we examined the effects of acute exposure on human organotypic bronchial epithelial culture and alveolar tri-culture models to an aerosol generated by an e-vapor device that uses the MESH™ technology (IQOS® MESH, Philip Morris International) and to CS from the 3R4F reference cigarette. In contrast to 3R4F CS exposure, exposure to the IQOS MESH Classic Tobacco aerosol did not cause cytotoxicity in either of the two lung culture models, despite resulting in greater concentrations of deposited nicotine. Ciliary beating frequency in bronchial cultures was not impacted in response to IQOS MESH aerosol exposure, whereas CS exposure caused a marked decrease in the frequency and the cilia beating active area. We complemented the histological and functional findings with quantitative analysis of the molecular changes in the exposed cultures. Global mRNA expression profiles and secreted protein profiles revealed a significantly lower impact of exposure to IQOS MESH aerosol than to 3R4F CS exposure. Overall, our study using whole aerosols for the exposure shows a much reduced impact of IQOS MESH aerosol in comparison to CS exposure in both bronchial and alveolar cultures, even at greater nicotine doses.