Assessing the Skin Sensitizing Potential of Constituents and Leachables from Wearable Devices Using GARDskin and Associated Applications

Pre-clinical toxicological evaluation is an essential component of ensuring the safety and compatibility of wearable devices with biological systems. Along with the local endpoints of cytotoxicity and irritation, skin sensitization is a core toxicological endpoint. Testing wearable devices, which are often solid and composed of multiple components, presents new challenges for New Approach Methods. In the current proof-of-concept study, we propose a strategy for conducting risk assessment of the individual components and the leachables from wearable devices. The GARDskin Dose-Response assay (OECD TGP 4.106) was used to predict the skin sensitization potency of three acrylate monomers, two acrylamide monomers, and one reactive dye. The GARDskin Medical Device (ISO 10993-10:2021, Annex C) was used to classify MED-2000 extracts spiked with isobornyl acrylate. All chemicals were classified as skin sensitizers. The quantitative potency predictions correlated well with available data from defined approaches and produced near-identical potency rankings. Available human and animal reference data were too sparse and heterogenous to substantiate agreement in potency. Finally, the GARDskin Medical Device assay correctly classified the spiked extract as skin sensitizing. In conclusion, the GARDskin assay and associated applications are well adapted to address the testing requirements for wearable devices.