Non-Invasive Assessment of Hair Regeneration in Androgenetic Alopecia Mice In Vivo Using Two-Photon and Second Harmonic Generation Imaging

The study involved 66 male C57BL/6 mice and used non-invasive two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) imaging techniques to assess hair regeneration in androgenetic alopecia (AGA) mice. The TPEF imaging revealed that the growth period and the alternation of new and old hair shafts in AGA mice were delayed due to testosterone. SHG imaging found that testosterone reduced hair follicle area and miniaturized hair follicles. These techniques provide a non-invasive approach for assessing hair regeneration in AGA mice and could potentially be used for evaluating drug-induced hair regeneration in humans. However, the limited penetration depth of these imaging techniques remains a challenge.