addressing the challenges of E-cigarette safety profiling by assessment of pulmonary toxicological response in bronchial and alveolar mucosa models.

Introduction:
This text provides an in-depth analysis of the safety profile of electronic cigarettes (ECIGs) and the challenges associated with their regulation. The study compares the particle number concentration, chemical composition, and response of physiologically relevant human bronchial and alveolar lung mucosa models to ECIG aerosols with and without nicotine. The findings highlight the influence of flavor, nicotine content, vaping regime, and the region of the respiratory tree on ECIG toxicity.

Key Points:

* The study used third-generation electronic nicotine delivery systems with refillable and exchangeable tank options to generate ECIG aerosols.
* Two sweet mixed fruit flavored ECIG liquids with and without nicotine were used for experimental purposes.
* a low intensity vaping regime was considered for short-term repeated exposure, leading to a total of 60 puffs and 30 puffs for bronchial and alveolar models, respectively.
* a portable laser spectrometer was used to measure the particle number concentration and particle size distribution of the ECIG aerosols.
* Twelve compounds commonly reported to be present in ECIG aerosols were screened using gas chromatography with flame ionization detection.
* human primary bronchial epithelial cells and representative human type II alveolar cells were cultured at air-liquid interface to develop physiologically relevant bronchial- and alveolar mucosa models.
* The study found that ECIG toxicity is influenced by a combination of multiple factors, including flavor, nicotine content, vaping regime, and the region of the respiratory tree.

Main Message:
The study underscores the need for multi-disciplinary approaches for comprehensive safety profiling of ECIGs. The findings highlight the importance of considering various factors, such as flavor, nicotine content, vaping regime, and the region of the respiratory tree, when assessing ECIG toxicity. The lack of long-term toxicity data and a systematic risk assessment strategy poses significant challenges for regulators to outline evidence-based policy recommendations. Therefore, a comprehensive and coordinated effort from researchers, regulators, and the industry is required to ensure the safe use of ECIGs.

Ganguly K, Nordström a, Thimraj Ta, et al. addressing the challenges of E-cigarette safety profiling by assessment of pulmonary toxicological response in bronchial and alveolar mucosa models. Scientific reports. 2020;10(1):20460. doi:10.1038/s41598-020-77452-w