a lower impact of an acute exposure to electronic cigarette aerosols than to cigarette smoke in human organotypic buccal and small airway cultures was demonstrated using systems toxicology assessment.

Introduction:
This article presents a study that aimed to compare the biological impact of an acute exposure to electronic cigarette (EC) aerosols and cigarette smoke (CS) using human organotypic air-liquid interface buccal and small airway cultures. The study measured the concentrations of nicotine and carbonyls deposited in the exposure chamber after each exposure experiment and assessed the impact of exposure on various biological endpoints, including histopathology, ciliary beating frequency, and the expression of inflammatory mediators and whole-genome transcriptomes.

Key points:

* The study used three different EL prototype formulations and MarkTen® EC devices to generate EC aerosols.
* CS was generated from 3R4F reference cigarettes using a 30-port carousel smoking machine.
* The particle size distribution of the EC aerosols and CS was measured using the aerodynamic Particle Sizer®.
* Organotypic human buccal epithelial and small airway epithelial cultures were used and exposed to EC aerosols and CS at their apical sides.
* The concentrations of nicotine and carbonyls deposited in the exposure chamber were measured after each exposure experiment.
* The impact of exposure was assessed by conducting histological assessment, measuring ciliary beating frequency, and profiling the expression of inflammatory mediators and whole-genome transcriptomes.

Main message:
The study found that exposure to EC aerosols resulted in minimal biological impact compared to CS exposure. The EC aerosols did not cause tissue damage, and the concentrations of nicotine and carbonyls deposited in the exposure chamber were significantly lower than those of CS. The study also found that the cellular responses to EC aerosol exposure were tissue type-specific, but the alterations were much smaller than those following CS exposure. The study suggests that EC aerosols are likely to be far less harmful than combustible tobacco cigarette use, and the absolute risks of the product cannot be determined at present. however, understanding the health effects of EC requires the determination of not only the risk of using them but also the biological effects relative to those of combustible tobacco cigarette use.

Iskandar aR, Zanetti F, Kondylis a, et al. a lower impact of an acute exposure to electronic cigarette aerosols than to cigarette smoke in human organotypic buccal and small airway cultures was demonstrated using systems toxicology assessment. Internal and emergency medicine. 2019;14(6):863-883. doi:10.1007/s11739-019-02055-x