Additives in vaping products, such as flavors, preservatives, or thickening agents, are commonly used to enhance user experience. Among these, Vitamin E acetate (VEA) was initially thought to be harmless but has been implicated as the primary cause of e-cigarette or vaping product use-associated lung injury, a serious lung disease. In our study, VEA serves as a proxy for other e-cigarette additives. To explore its harmful effects, we developed an exposure system to subject a pulmonary surfactant (PSurf) model to VEA-rich vapor. Through detailed analysis and atomic-level simulations, we found that VEA tends to cluster into aggregates on the PSurf surface, inducing deformations and weakening its essential elastic properties, critical for respiratory cycle function. Apart from VEA, our experiments also indicate that propylene glycol and vegetable glycerin, widely used in e-liquid mixtures, or their thermal decomposition products, alter surfactant properties. This research provides molecular-level insights into the detrimental impacts of vaping product additives on lung health.

Department of Physics University of Helsinki P O Box 64 00014 Helsinki Finland

InnoRenew CoE Livade 6a 6310 Izola Slovenia

Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nám 542 2 160 00 Prague Czech Republic

J Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences Dolejškova 2155 3 182 23 Prague Czech Republic

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