Examination of the skin barrier repair/wound healing process using a living skin equivalent (LSE) model and matrix-assisted laser desorption-ionization-mass spectrometry imaging (MALDI-MSI)

Objective: Examination of the skin barrier repair/wound healing process using a living skin equivalent (LSE) model and matrix‐assisted laser desorption/ionization‐mass spectrometry imaging (MALDI‐MSI) to identify lipids directly involved as potential biomarkers. These biomarkers may be used to determine whether an in vivo wound is going to heal for example if infected. Methods: An in vitro LSE model was wounded with a scalpel blade and assessed at day 4 post‐wounding by histology and MALDI‐MSI. Samples were sectioned at wound site and were either formalin‐fixed paraffin‐embedded (FFPE) for histology or snapped frozen (FF) for MSI analysis. Results: The combination of using an in vitro wounded skin model with MSI allowed the identification of lipids involved in the skin barrier repair/wound healing process. The technique was able to highlight lipids directly in the wound site and distinguish differences in lipid distribution between the epidermis and wound site. Conclusion: This novel method of coupling an in vitro LSE with MSI allowed in‐depth molecular analysis of the skin barrier repair/wound healing process. The technique allowed the identification of lipids directly involved in the skin barrier repair/wound healing process, indicating these biomarkers may be potentially be used within the clinic. These biomarkers will help to determine, which stage of the skin barrier repair/wound healing process the wound is in to provide the best treatment