The in vitro assessment of a novel vaping technology

Toxicol Rep. 2020 Aug 22:7:1145-1156. doi: 10.1016/j.toxrep.2020.08.016. eCollection 2020.

Abstract

We have developed a novel vaping product (NVP) IS1.0(TT), which utilises a stainless-steel mesh to transfer and vaporise the e-liquid, mitigating some of the potential sources of toxicants that can be generated using the more traditional 'wick and coil' approach. The emissions from IS1.0(TT) have previously been found to have lower levels of toxicants overall when directly compared with a commercial wick and coil e-cig. This current study assessed the toxicological responses to aerosols from this NVP. Responses induced by IS1.0(TT)were compared to those from a 3R4F reference cigarette, using in vitro test methods which included regulatory genetic toxicological assays as well as some more contemporary screening approaches. The experimental conditions were designed to facilitate the testing of aerosol from this vaping product at doses that in most cases greatly exceeded those of the 3R4F comparator showed little to no toxicological responses and demonstrated significantly reduced effects in these in vitro assays when compared to 3R4F. Furthermore, the extreme doses tested in the present study indicate that the toxicant profile of this NVP translates to lower biological activity in vitro, and suggests that the absolute risk hazard level associated with electronic cigarettes can be reduced through continuous improvement as the technology evolves.

Keywords: ACM, aerosol collected mass; ALI, air-liquid interface; ANOVA, analysis of variance; ARE, antioxidant response element; Aerosol; AqE, aerosol aqueous extract; AqE, aqueous aerosol extracts; CRM81, CORESTA recommended method number 81; Cigarette; DCF, 2′,7′ dichlorodihydrofluorescein; DMSO, dimethyl sulfoxide; DSB, double-strand break; Electronic cigarette; FDA, US Food and Drug Administration; GEF, global evaluation factor; GSH, glutathione (reduced form); HCI, Health Canada Intense; HUVEC, human umbilical vein endothelial cell; ISO, International Organisation for Standardisation; IVMn, in vitro micronucleus; In vitro; MF, mutant frequency; MLA, mouse lymphoma assay; NASEM, US National Academy of Sciences, Engineering and Medicine; NHBE, normal human bronchial epithelial; NRU, neutral red uptake; NVP, new vapour product; RWD, relative wound density; S9, post-mitochondrial supernatant; TPA, 12-O-tetradecanoylphorbol-13-acetate; TPM, total particulate matter; TobReg, WHO Study Group on Tobacco Product Regulation; WA, whole aerosol.