Considerations on dosimetry for in vitro assessment of e-cigarette toxicity

Abstract

Electronic cigarettes (or e-cigarettes) can be used as smoking cessation aid. Some studies tend to show that they are less hazardous than tobacco cigarettes, even if it does not mean they are completely safe. The huge variation in study designs assessing in vitro toxicity of e-cigarettes aerosol makes it difficult to make comparisons and draw robust and irrefutable conclusions. In this paper, we review this heterogeneity (in terms of e-cigarette products, biological models, and exposure conditions) with a special focus on the wide disparity in the doses used as well as in the way they are expressed. Finally, we discuss the major issue of dosimetry and show how dosimetry tools enable to align data between different exposure systems or data from different laboratories and therefore allow comparisons to help further exploring the risk potential of e-cigarettes.

In vitro toxicological evaluation of aerosols generated by a 4th generation vaping device using nicotine salts in an air-liquid interface system

“…Finally, nicotine can also exist in a variety of forms depending on its protonation state driven by pH of the solvent and nicotine pKa [ 42 ] and protonated nicotine salts can be generated with a variety of weak organic acids, including benzoic acid, salicylic acid, or lactic acid, among at least six others [ 43 ]. We have previously discussed the consequences of the heterogeneity of devices and e-liquids, which leads to a large number of in vitro studies with different experimental designs and aims, ultimately making consistent comparisons and robust conclusions on the toxicity of e-cigarette aerosols difficult [ 44 ]. The present study sought to overcome some of these limitations for the first time by assessing the individual toxicological effects of aerosols generated from e-liquid base components using a 4th generation Pod-Mod device.…”

“…Overall, dosimetry data are often inadequate or poorly reported and there is considerable variability between studies. This variability in deposited dose is mostly explained by the diversity in exposure setups, ranging from homemade boxes to automated puffing machines [ 44 ]. Depending on the exposure setup, a fraction of aerosol could be lost in tubing.…”

A Practical Framework for Novel Electronic Nicotine Delivery System Evaluation: Chemical and Toxicological Characterization of JUUL2 Aerosol and Comparison with Reference Cigarettes

“…Within the JUUL2 study, nicotine was chosen to characterize dosimetry across in vitro assays. The utilization of nicotine as a marker facilitates cross-product comparison and extrapolation of preclinical data and consumer use studies to help further explore the reduced risk potential of ENDS products [ 116 ].…”

Comparative study of the effects of cigarette smoke versus next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes

“…In the corresponding literature, various normalization factors, e.g. number of puffs, percentages, or nicotine amounts are used for the application of smoke extracts in vitro and in vivo [ 23 , 55 , 66 , 76 ]. In order to compare effects in different smoking studies, it is mandatory to state and consider the detailed product specifications.…”