Noninvasive Detection of Skin Cancer by Imprint Desorption Electrospray Ionization Mass Spectrometry Imaging

Abstract

We report a technique for the noninvasive detection of skin cancer by imprint desorption electrospray ionization mass spectrometry imaging (DESI-MSI) using a transfer agent that is pressed against the tissue of interest. By noninvasively pressing a tape strip against human skin, metabolites, fatty acids, and lipids on the skin surface are transferred to the tape with little spatial distortion. Running DESI-MSI on the tape strip provides chemical images of the molecules on the skin surface, which are valuable for distinguishing cancer from healthy skin. Chemical components of the tissue imprint on the tape strip and the original basal cell carcinoma (BCC) section from the mass spectra show high consistency. By comparing MS images (about 150μm resolution) of same molecules from the tape strip and from the BCC section, we confirm that chemical patterns are successfully transferred to the tape stripe. We also used the technique to distinguish cherry angiomas from normal human skin by comparing the molecular patterns from a tape strip. These results demonstrate the potential of the imprint DESI-MSI technique for the noninvasive detection of skin cancers as well as other skin diseases before and during clinical surgery.

Evaluation of Oil-Absorbing Film for Imprint Desorption Electrospray Ionization Mass Spectrometry Imaging (IDESI-MSI) on Biological Samples

“…For this purpose, the imprint material is required to transfer as much of the species as possible from the sample surface and retain the original distribution of detected molecules. Previously, the imprint desorption electrospray ionization mass spectrometry imaging (IDESI-MSI) techniques were reported to be successfully applied on various materials, such as thin layer chromatography (TLC) surface [ 26 ], tape [ 27 ], polytetrafluoroethylene (PTFE) [ 24 , 26 ], and porous silicon (pSi) [ 26 ]. In this study, we developed a new material, an oil-absorbing film, for IDESI-MSI on biological samples.…”