In Vitro Cytotoxicity in MucilAir™ Tissues Exposed to Whole Aerosol from a Combustible Cigarette and Electronic Nicotine Delivery System

LIVe 2022 -- There is a current push to investigate the toxicity of emerging Next Generation Products (NGPs) including Electronic Nicotine Delivery System (ENDS) and Heated Tobacco Product (HTP) products. 3D airway tissue models are a relevant method for analysis of toxicity for these aerosol products. MucilAir™ (Epithelix Sarl, Switzerland) tissues were exposed using a Vitrocell® VC10® smoking robot to 1R6F Kentucky Reference cigarettes, a commercially available HTP and a commercially available ENDS. Liquid traps were placed at the air liquid interface (ALI) and analysed for nicotine, which was used as a marker for delivered dose. Lactate dehydrogenase (LDH) release and WST-8 assessments were used to assess cytotoxicity. WST-8 assessments showed 1R6F cigarettes and the HTP induced a dose-related response. The ENDS-treated tissues showed a cytotoxic response at undiluted dose only. LDH release for 1R6F-tested tissues gave an increase in toxicity at all doses compared to ALI control. For the HTP concentration, related increases were seen across the doses. ENDS showed a significant increase in toxicity at the undiluted dose. Statistical differences were observed between airflows with WST-8 and LDH (p>0.005). Comparisons between the product types were conducted using WST-8, with significance between 1R6F and HTP vs. ENDS (p>0.005). This study was a proof of concept, suggesting that MucilAir™ tissue modules can be used to differentiate between combustible cigarettes or HTP and ENDS products with regard to cytotoxicity assessment using WST-8.