In vivo multiphoton tomography: a non invasive powerful tool for biochemical investigation of human skin

摘要

In vivo simultaneous collagen and elastin measurements using the multiphoton tomograph Dermalnspect have been performed in skin dermis. We showed it was possible to get simultaneous measurements of autofluorescence (AF) and Second Harmonic Generation (SHG) with a newly developed device using 2 PMTs for time-correlated single photon counting. Unlike elastin (AF), collagen structures are able to generate second harmonics (SHG). Comparing the images and SHG / AF ratios recorded in the depth of the outer and inner sides of the forearm of two European female volunteers (31 and 60 years old, respectively) shows differences in collagen and elastin fibres density. It decreases with depth in the 60 years old volunteer compared to the younger one, and the skin of younger volunteer shows more collagen.