Cytotoxicity of Common Solvents used in Liquid Nicotine Formulations

Principal Investigators: Jake McDonald and Wanyoike Kang'ethe

Funding Mechanism: Research Contract

ID number: HHSF223201510001I

Award Date: 9/7/2017

Institution: Lovelace Biomedical and Environmental Research Institute

This study aims to establish the baseline toxicity of propylene glycol (PG) and vegetable glycerin (VG), the primary solvents in e-liquid, as well as the effect of temperature and heating element composition on solvent-induced cytotoxicity (cell toxicity) with and without nicotine co-exposure. The first part of the study will involve measurement of in vitro cellular toxicity using human bronchial epithelial cells. The cells will be exposed to e-cigarette aerosol produced with e-liquid mixtures with varying ratios of PG and VG. The second part of the study will involve separately changing two parameters: (1) the power output of the device relative to the setting used in the first part of the study, and (2) the constituent materials used in the heating element. The heating element materials tested will include Kanthal, nichrome, stainless steel and ceramic; the solvent formulations used will be the three formulations that showed the greatest cytotoxicity in the first part of the study. Chemical characterization of the aerosol will include identification and quantification of chemical constituents, total particulate matter (TPM), pH, and particle size distribution. Study findings may inform the development of a potential in vitro toxicity screening protocol for e-cigarettes.