Reliability of fourier transform infrared spectroscopy in the characterization of human skin

Abstract

Fourier transform infrared (FT-IR) spectroscopy, an organic molecule characterizing tool, is used here to differentiate young (36 ? 2.87 years) and aged (78 ? 1.25 years) skins, based on glycosaminoglycan (GAG) and protein functional groups. Female breast mas-tectomy-skin, FT-IR spectroscopy revealed intensity differences that were quantified on GAG and protein standard curves, and assigned to the corresponding functional groups. Band intensity reductions at 78- years include: 34.37% (w/w) ?1259 - 1223 cm–1, sulfate (SO42–)/sulfonate (SO3–) S=O/phosphate (PO42?) P=O stretch?; 32.00% (w/w) (1383-1262 cm-1, GAG- methyl C-H/C-C-H); and 35.60% (w/w) ?1738 - 1646 cm–1, C=O stretch: N-acetylated GAG’s, Amide I, and others?. Intensity increments at 78-years are 63.32% (w/w) (1636 - 1523 cm–1, Phe/Trp/Tyr-C=C, Amide II); 27.02% (w/w) [1511 - 1457 cm–1, protein ?(CH2)/ ?(CH3) stretch]; and 41.90% (w/w) (1218 - 1139 cm–1, Phe/Trp/Tyr C-H/C-N/C-C6H5 vibrations). The data speak to the power of FT-IR spectroscopy as a non-invasive tool to diagnose tissue disorders such as skin, liver, kidney or any other type that would require a noninvasive tool like FT-IR, to prevent further dam-age during the diagnosis. These results also demon-strate an age-mediated decrease of skin-GAG content, and GAG-N-acetylation, in addition to protein com-position concentration increments.