Enhanced hair growth effects through low-level vortex beams radiation: An experimental animal study.

Photobiomodulation therapy (PBMT) is a non-invasive and pain-less treatment for hair loss. Researches on PBMT rarely considered the impact of different light structures. In this study, we irradiated shaven rats with both 650 nm, m = 32 vortex beams and ordinary Gaussian beams. The laser treatment was performed at 24-hour intervals for 20 days. The energy density was set to 4.25 J/cm2 . The results indicated that low-level vortex beam irradiation led to better stimulation of hair growth than the Gaussian beams, which might be related to deeper penetration. The underlying biological mechanisms are discussed in terms of the activation of Wnt/β-catenin/sonic hedgehog pathway. Our results suggest that low-level vortex beam irradiation is advantageous to the treatment of hair loss because it is technically feasible, convenient and effective.