Translating chemometric analysis into physiological insights from in vivo confocal Raman spectroscopy of the human stratum corneum

• Published in: Biochimica et biophysica acta. Biomembranes 2019-02, Vol.1861 (2), p.403-409
• Main Authors: Perticaroli, Stefania, Yeomans, Dawn J., Wireko, Fred C., Webber, John T., Werchowski, Kathy M., Cambron, R. Thomas, Ray, Paula J.
• Format: Article
• Language: English
• Subjects: Keratin; Lipid organization; Multivariate curve resolution; Natural moisturizing factor; Skin barrier
• ISSN: 0005-2736; 1879-2642
• DOI: 10.1016/j.bbamem.2018.11.007

The superficial layer of the skin, the stratum corneum (SC), consists of corneocytes surrounded by lipid regions and acts as a protective barrier for the body against water loss, toxic agents and microorganisms. As most substances permeate the stratum corneum through the lipid regions, lipid organization is considered crucial for the skin barrier function. Here, we investigate the potential of in vivo confocal Raman spectroscopy to describe the composition and organization of the SC. Confocal Raman spectroscopy is finding increasing use in the characterization of skin in biomedical, pharmaceutical and cosmetic applications. In this work, we analyze the spectra using chemometric methods and obtain principal components that correspond to the primary skin constituents: protein (keratin), natural moisturizing factor (NMF), water and lipid contributions in both ordered (orthorhombic) and disordered structural organization. By identifying these important components of the SC, these results highlight the utility of this in vivo, non-invasive, and depth resolved tool at the forefront of skin research. [Display omitted] •Chemometric analysis of in vivo confocal Raman spectra of human stratum corneum finds components corresponding to protein, NMF, water and lipids.•Lipid organization is crucial for the skin barrier function. Our approach detects SC lipids in ordered and disordered structural organization.