The etiology of skin sensitisation is a complex process that is comprised of several biological processes that include haptenisation, signalling pathway activation, changes in gene expression, immune activation and cell damage. This complexity can make it difficult to assess skin sensitisation in vitro, and is often most successfully evaluated with a combination of assays.
ECVAM has completed validation and the OECD has released test guidelines for two in vitro, non-animal assays, the Direct Peptide Reactivity Assay (DPRA) and KeratinoSens™ for evaluation of in vitro skin sensitisation. Each assay evaluates a discrete mechanism of toxic response or other adverse outcome, which is why a multi-pronged approach may be required. While the DPRA and KeratinoSens™ assays are highly predictive and useful for compounds and simple mixtures, they aren’t always suitable for testing finished products like creams or lotions.
By contrast, SenCeeTox® is a multi-parametric assay that utilises a 3D cellular model in tandem with in silico computation. Because it employs a reconstructed human epidermal model, it can be used to test finished products, formulations and complex mixtures.
The table below provides an overview of the capabilities and characteristics of each assay.