A contextualised e-cigarette testing strategy shows flavourings do not impact lung toxicity in vitro

Area of Science:

• Toxicology
• In vitro toxicology
• Tobacco harm reduction

Background:

• Smoking cessation is a major public health goal.
• Electronic cigarettes and their flavors are increasingly used by smokers transitioning from combustible cigarettes.
• Assessing the reduced risk potential of e-cigarette aerosols and flavors is crucial.

Purpose of the Study:

• To provide evidence supporting the reduced risk potential of e-cigarette aerosols and flavors.
• To assess commercially available e-liquids using in vitro screening and whole aerosol exposure models.
• To compare the toxicity of e-cigarette aerosols to cigarette smoke.

Main Methods:

• Utilized a 2D in vitro screening approach for commercially available e-liquids (Vuse ePod).
• Analyzed selected flavors using a 3D MucilAir whole aerosol exposure model.
• Measured toxicity and functional endpoints including Trans Epithelial Electrical Resistance (TEER), Cilia Beat Frequency (CBF), and Active Area, comparing to 1R6F research cigarette smoke.

Main Results:

• Aerosolized flavored e-liquids did not increase overall measured aerosol toxicity compared to cigarette smoke.
• In vitro cellular toxicity of flavored e-cigarette products was over 95% reduced compared to cigarette smoke toxicity, using a point of departure (IC80) approach.
• Overall product toxicity was not increased in a flavor-dependent manner.

Conclusions:

• Flavored e-cigarette products demonstrate significantly reduced toxicity compared to traditional cigarette smoke.
• These findings indicate that appropriately stewarded flavored e-cigarette products can play a role in tobacco harm reduction.
• The study supports the potential of e-cigarettes as a less harmful alternative for smokers.