Skin aging is characterized by cellular and molecular alterations. In this context, Confocal Raman spectroscopy was used in vivo to measure these biochemical changes as function of the skin depth. In this study we have tried to correlate spectra from pure amino acids to in vivo spectra from volunteers with different ages. This study was performed on 32 volunteers: 11 from Group A (20-23 years), 11 from Group B (39-42 years) and 10 from Group C (59-62 years). For each group, the Raman spectra were measured on the surface (0 µm), 30 ± 3 µm and 60 ± 3 µm below the surface. The results from intergroup comparisons showed that the oldest group had a prevalence of the tyrosine band, but it also presented a decrease in the band centered at 875 cm-1 of pyrrolidone acid. The amide I band centered at 1637 cm-1 that is attributed to collagen, as well as other proteins and lipid, showed a smaller amount of these biomolecules for Group C, which can be explained by the decrease in collagen concentration as a function of age.
Human skin; Amino acids; Raman spectroscopy
