Three regulatory accepted in vitro assays were evaluated in a proof-of-concept project to determine skin sensitization potential of electronic cigarette liquids (eliquids). These assays measure molecular initiating events and initial cellular responses prescribed in the OECD Integrated Testing Strategy (ITS) describing key events in the adverse outcome pathway (AOP) leading to skin sensitization.
There is an increasing need for researchers to understand the dynamic aspects of inhaled tobacco product exposure. Available 3D human reconstructed airway tissues (RHuA) provide researchers with a more physiological platform that offers apical and basal compartments for flexibility in modelling relevant exposures. We have tested the Tecan D300 digital dispenser as potential technical solution to deliver precise amounts of very small vehicle droplets to coat the apical surface of an available RHuA.
One of the current goals of the United States Environmental Protection Agency Office of Pesticide Programs (US EPA OPP) is to replace by non-animal testing methods as many of the endpoints of the battery of acute toxicity tests known as the “6-pack” as possible. One of the “6-pack” tests is the Draize rabbit test for dermal irritation. We investigated whether the validated in vitro Skin Irritation Test (SIT, OECD TG 439) can be used to determine US EPA OPP dermal hazard category assignment.
Regulatory restrictions on animal use have increased the reliance of risk assessors and regulators on in vitro test systems. Ideally, tissue-based assays could replace the animal studies as follow-up tools to verify results from standard in vitro assays. The RSMN assay combines the EpiDerm™ 3D reconstructed skin (RS) model with the micronucleus (MN) assay to provide a more realistic model for evaluating the genotoxic potential of dermally applied chemicals or products, such as cosmetics.
Presented at the National Academies of Sciences, Engineering, and Medicine's (NAS) workshop on electronic nicotine delivery systems (ENDS), e-cigarettes.
Presented at the 2nd Good Laboratory Practice Compliance Summit, January 26-27, 2017, Arlington, VA
Source: In Vitro Exposure Systems and Dosimetry Assessment Tools for Inhaled Tobacc…
Progress within the in vitro toxicology field has made available testing platforms based on reconstructed tissue models that are validated to address the skin corrosion and irritation endpoints. While the validated in vitro assays can be used for the hazard identification of chemicals irritant to skin in accordance with the United Nations (UN) Globally Harmonized System (GHS) for Classification and Labeling of Chemicals, they were not calibrated to address the classification system used by the United States Environmental Protection Agency (US EPA).
Source: Pan-American Conference on Alternatives