Avaliação dos efeitos fototérmico do laser de diodo λ1470 nm na pele em modelo experimental de ratos.

Abstract

The subdermal high-power diode laser is a therapy that has been frequently used as a treatment for skin aging. However, there is a need for studies to verify morphological and molecular changes in the skin triggered by this light technology. Thus, the objective of the present study was to evaluate the photothermal effects of diode laser wavelength (λ) 1470 nm on the skin of rats. 20 male Wistar rats were used, randomized into 2 groups: placebo laser (LP): treatment with subdermal laser turned off; active laser (LA): subdermal laser treatment was used. For therapy, high-power diode laser equipment was used (λ = 1470 nm; P = 2 W; beam area = 240 μm; beam divergence in rad: 0.227; continuous mode), applied in 5 subdermal vectors in the region of the animal's back in an area of 24 cm2 depositing an average of energy of 85 J/cm2, in a single session and the tissue was evaluated 15 days after the intervention. To evaluate the effects of the treatment, histological, morphometric analyzes and immunoexpression of transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) were performed. The results demonstrated that active laser animals showed a better arrangement of collagen fiber bands and an increase in the thickness of the dermis and the number of vessels. Furthermore, animals treated with active laser showed an increased immunoexpression of TGF-β and VEGF compared to placebo. Thus, we can conclude that the subdermal high-power diode laser proves to be a promising option in aesthetic dermatology, as it was capable of increasing vascularization and the expression of factors that enhance skin rejuvenation.