Probing the human epidermis by combining ToF-SIMS and multivariate analysis

Area of Science:

• Biomedical Engineering
• Materials Science
• Dermatology

Background:

• The mammalian epidermis forms a crucial barrier against environmental threats.
• Skin pathologies can disrupt epidermal barrier function, often with complex molecular underpinnings.
• Understanding molecular changes in the epidermis is vital for treating skin diseases.

Purpose of the Study:

• To develop a reproducible methodology for characterizing the human epidermis using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).
• To apply ToF-SIMS to an in vitro model of the human epidermis, specifically reconstructed human epidermis (RHE).
• To extract meaningful biological information and distinguish epidermal layers using multivariate analysis.

Main Methods:

• Static ToF-SIMS characterization of RHE cryosections.
• High mass and high lateral resolution acquisitions.
• Principal Components Analysis (PCA) for multivariate data analysis.

Main Results:

• Successful distinction between cornified layers and metabolically active epidermal cells using PCA on ToF-SIMS data.
• Demonstration of ToF-SIMS's capability to extract biologically relevant spectral features.
• Validation of the methodology for producing experimental replicates in RHE models.

Conclusions:

• ToF-SIMS, combined with PCA, provides a powerful and reproducible method for characterizing the human epidermis at a molecular level.
• This approach enhances the study of skin barrier function and the molecular basis of skin pathologies.
• The methodology facilitates reliable ex vivo analysis of epidermal models, aiding in research and therapeutic development.