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ICCVAM Biennial Report 2020-2021

Biennial Progress Report 2020-2021 Interagency Coordinating Committee on the Validation of Alternative Methods

Two-dimensional Cellular and Three-dimensional Bioprinted Skin Models to Screen Topical-use Compounds for Irritation Potential

Assessing skin irritation potential is critical for the safety evaluation of topical drugs and other consumer products such as cosmetics. Use of animals for these evaluations is prohibited in some sectors, with advanced in vitro cellular models considered as possible replacements. To compare the utility of different cellular skin models for this purpose, scientists at NCATS, the National Eye Institute, and NIEHS assessed irritation potential in different cellular skin models compatible with high-throughput screening platforms (Wei et al. 2020). The study tested 46 compounds related to topical products on monolayer keratinocytes, reconstructed human epidermis, and full-thickness skin models, and evaluated performance of the models using generally accepted cellular and molecular indicators of irritant activity. The study indicated that using human cells to generate bioprinted tissue is a quick and reliable method to model human skin in a high-throughput manner, and that this approach could be used as evidence for hazard labeling in a variety of hazard classification systems.