title: Vapours of US and EU Market Leader Electronic Cigarette Brands and Liquids Are Cytotoxic for Human Vascular Endothelial Cells.
abstract: The present study was conducted to provide toxicological data on e-cigarette vapours of different e-cigarette brands and liquids from systems viewed as leaders in the e-cigarette market and to compare e-cigarette vapour toxicity to the toxicity of conventional strong high-nicotine cigarette smoke. Using an adapted version of a previously constructed cigarette smoke constituent sampling device, we collected the hydrophilic fraction of e-cigarette vapour and exposed human umbilical vein endothelial cells (HUVECs) to the mixture of compounds present in the vapour of 4 different single-use e-cigarettes, 6 different liquid vapours produced by the same refillable e-cigarette, and one e-cigarette with an exchangeable liquid cartridge. After incubation of cells with various concentrations and for various periods of time we analysed cell death induction, proliferation rates, the occurrence of intra-cellular reactive oxygen species, cell morphology, and we also measured e-cigarette heating coil temperatures. Overall, conventional cigarette smoke extract showed the most severe impact on endothelial cells. However, some e-cigarette vapour extracts showed high cytotoxicity, inhibition of cell proliferation, and alterations in cell morphology, which were comparable to conventional high-nicotine cigarettes. The vapours generated from different liquids using the same e-cigarette show substantial differences, pointing to the liquids as an important source for toxicity. E-cigarette vapour-mediated induction of oxidative stress was significant in one out of the 11 analysed vapours. There is a high variability in the acute cytotoxicity of e-cigarette vapours depending on the liquid and on the e-cigarettes used. Some products showed toxic effects close to a conventional high-nicotine cigarette. Liquid nicotine, menthol content, and the formation of acute intracellular reactive oxygen species do not seem to be the central elements in e-cigarette vapour toxicity.
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.|MCI Management Center Innsbruck, Biotechnology, Innsbruck, Austria.
authors.forename: Raphaela
authors.initials: R
authors.lastname: Putzhammer
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Doppler
authors.affiliation: Austrian Drug Screening Institute GmbH, Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jakschitz
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Heinz
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.|MCI Management Center Innsbruck, Biotechnology, Innsbruck, Austria.
authors.forename: Juliane
authors.initials: J
authors.lastname: Förste
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Katarina
authors.initials: K
authors.lastname: Danzl
authors.affiliation: Cardiac Surgery Research Laboratory, Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Messner
authors.affiliation: Cardiac Surgery Research Laboratory, University Clinic for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Bernhard
mesh_terms: D016923:Cell Death; D049109:Cell Proliferation; D002478:Cells, Cultured; D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects* / Q000145:classification / Q000191:economics; D005062:European Union; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects*; D006801:Humans; D009538:Nicotine / Q000633:toxicity*; D018384:Oxidative Stress; D014481:United States
chemical_list: D009538:Nicotine