Determinants of skin sensitisation potential

Area of Science:

• Toxicology
• Dermatology
• Computational Chemistry

Background:

• Skin sensitisation is a significant toxicological concern for workplace and consumer chemicals.
• European regulations like REACH mandate assessment of sensitising potential, driving the need for non-animal testing methods.
• Existing research focuses on predicting skin sensitisation without animal testing, spurred by regulatory changes.

Purpose of the Study:

• To investigate non-animal based prediction of skin sensitisation using a mechanistic approach.
• To identify the critical chemical properties determining a substance's sensitising potential.
• To propose a chemistry-based strategy for predicting skin sensitisation.

Main Methods:

• Analysis of the mechanistic stages of skin sensitisation, from chemical exposure to T-cell activation.
• Evaluation of the dependency of each stage on the chemical properties of the sensitiser.
• Development of a prediction strategy based on reaction mechanistic domain assignment, reactivity, hydrophobicity, and quantitative mechanistic modelling (QMM) or read-across.

Main Results:

• Penetration, Langerhans cell migration, and antigen recognition are generally not the primary determinants of sensitisation potential.
• Covalent binding to carrier proteins is identified as the major structure-dependent factor influencing skin sensitisation potential.
• The proposed chemistry-based strategy leverages chemical properties for prediction.

Conclusions:

• Chemicals' ability to bind covalently to proteins is the most critical factor in determining skin sensitisation potential.
• A mechanistic, chemistry-based approach offers a viable strategy for predicting skin sensitisation without animal testing.
• This approach supports regulatory compliance and enhances chemical safety assessments.