2P-21 PDF
Visualizing NMF distribution across the human face by 2D-DESI MS imaging of tape-stripped stratum corneum
Natural moisturizing factor (NMF) is a mixture of hygroscopic small molecules that are essential to maintain hydration and barrier homeostasis of stratum corneum (SC). Although differences of NMF distribution in the human face have already been reported, fine molecular distribution information related to anatomical structures could not be obtained due to the limitations of the conventional method, which involves liquid extraction and chromatographic separation. As a way to break through the situation, we applied two dimensional desorption electrospray ionization mass spectrometry imaging (2D-DESI MSI) for the direct NMF distribution analysis of SC collected by tape-stripping . After careful optimization of 2D-DESI MSI parameters, 16 major and important NMF molecules such as serine, pyrrolidone carboxylic acid, histidine, and urocanic acid were detected by a combination of positive and negative detection modes. In the analysis of the half-face, SCs collected from 8 different sites of one side of the face of volunteers were analyzed by 2D-DESI MSI at 500um spatial resolution. The result showed that each NMF molecular distributions/conversions had unique patterns across the face, suggesting molecular dynamisms in the SC. Potentials and limitations of 2D-DESI MSI for molecular distribution analysis on the human face will be discussed in the presentation.