Comparison of electronic cigarette refill fluid cytotoxicity using embryonic and adult models

Electronic cigarettes (EC) and refill fluids are distributed with little information on their pre- and postnatal health effects. This study compares the cytotoxicity of EC refill fluids using embryonic and adult cells and examines the chemical characteristics of refill fluids using HPLC. Refill solutions were tested on human embryonic stem cells (hESC), mouse neural stem cells (mNSC), and human pulmonary fibroblasts (hPF) using the MTT assay, and NOAELs and IC50s were determined from dose–response curves. Spectral analysis was performed when products of the same flavor had different MTT outcomes. hESC and mNSC were generally more sensitive to refill solutions than hPF. All products from one company were cytotoxic to hESC and mNSC, but non-cytotoxic to hPF. Cytotoxicity was not due to nicotine, but was correlated with the number and concentration of chemicals used to flavor fluids. Additional studies are needed to fully assess the prenatal effect of refill fluids.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Electronic cigarette refill fluids were examined for cytotoxicity. ► Embryonic cells were more sensitive to refill fluid than adult lung cells. ► Flavorings, but not nicotine, were linked to toxicity. ► Refill products varied from non-cytotoxic to highly cytotoxic. ► Products from two companies were cytotoxic to embryonic cells but not lung cells.