Development of an in vitro cytotoxicity model for aerosol exposure using 3D reconstructed human airway tissue; application for assessment of e-cigarette aerosol

Introduction:
This text describes a study that aimed to develop a protocol to evaluate the acute irritant potential of e-cigarette aerosols using qCM technology and a commercially available human 3D airway tissue model, Epiairway™. The study also investigated exposure parameters specific to e-cigarette aerosol testing in vitro using the VC 10 exposure system.

Key points:

* The study used Epiairway™ tissues, which are 3D, fully differentiated in vitro reconstructions of primary human tracheobronchial epithelium.
* The tissues were exposed to liquid test articles, cigarette smoke, and e-cigarette aerosol using the VITROCELL/C210smoking robot and a 12/6 CF stainless-steel exposure module.
* The qCM dose tools were used to quantify the delivery of e-cigarette aerosol to the surface of the cell cultures.
* The results showed that e-cigarette aerosol and aerosol formulations tested in this study were significantly less irritant when compared to cigarette smoke generated from a 3R4F reference product over an equivalent 6 h exposure timeframe.
* The study also demonstrated that the VITROCELL/C210system is compatible with the use of cells at the air-liquid interface, and can deliver intact aerosol to cell culture systems.
* The exposure parameters investigated in the study included airflow, vacuum rate, and exposure time.
* The study used a 25 mL/min vacuum rate and a diluting airflow rate of 1.0 L/min for the duration of the study.

Main message:
The study demonstrates the potential of using Epiairway™ tissues and the VITROCELL/C210system for the assessment of e-cigarette aerosols. The results suggest that e-cigarette aerosol and aerosol formulations tested in this study are significantly less irritant when compared to cigarette smoke. The study also provides valuable information on the exposure parameters that are specific to e-cigarette aerosol testing in vitro. Overall, the study supports the use of more physiologically relevant in vitro toxicity test systems for the assessment of e-cigarette aerosols.

Neilson, Louise, Courtney Mankus, David Thorne, George Jackson, Jason DeBay, and Clive Meredith. “Development of an in Vitro Cytotoxicity Model for aerosol Exposure Using 3D Reconstructed human airway Tissue; application for assessment of e-Cigarette aerosol.” Toxicology in Vitro 29, no. 7 (October 2015): 1952–62. https://doi.org/10.1016/j.tiv.2015.05.018.