Efeitos da fotobiomodulação associada ao polidesoxirribonucleico em fibroblastos dérmicos humanos

Abstract

Skin aging is a multifactorial process characterized by reduced fibroblast activity, decreased collagen and elastin production, accumulation of reactive oxygen species, and disorganization of the extracellular matrix. These changes lead to loss of skin firmness, elasticity, and function, affecting both appearance and quality of life. Therefore, understanding cellular mechanisms and developing treatments capable of minimizing or reversing these deleterious effects is essential. In this context, photobiomodulation with red (R, 660 nm) and infrared (IR, 810 nm) light has emerged as a promising strategy for skin regeneration, as it can modulate key cellular processes such as proliferation, extracellular matrix synthesis, and repair of oxidative damage. In parallel, polydeoxyribonucleotide (PDRN), a low–molecular weight DNA derivative, exhibits biostimulatory properties by activating purinergic A2A receptors and inducing endogenous growth factors, positively impacting wound healing and dermal remodeling. This in vitro study evaluated the effects of red (660 nm) and infrared (810 nm) photobiomodulation and polydeoxyribonucleotide (PDRN), applied alone or in combination, on cell viability and the expression of genes related to extracellular matrix components. Human dermal fibroblasts (HFF-2 cell line) were divided into the following groups: control, PDRN 1 mg, PDRN 500 µg, red light (R), infrared light (IR), and the combinations R–PDRN 1 mg, R–PDRN 500 µg, IR–PDRN 1 mg, and IR–PDRN 500 µg. Irradiation was performed using a 660 nm LED with an energy of 8.16 J and an 810 nm LED with an energy of 10.37 J. The results demonstrated that after 24 h all groups maintained cell viability, with no evidence of cytotoxicity. At 48 and 72 h, a statistically significant difference was observed, with the IR–PDRN combination showing higher viability compared to the isolated treatment groups. Regarding extracellular matrix components, a significant increase in the expression of COL1A1, COL3A1, TGFβ, and elastin was observed in all treated groups compared with the control group. In conclusion, the findings indicate that both PDRN and infrared LED irradiation exert positive effects on human dermal fibroblasts, enhancing cell viability and the synthesis of extracellular matrix components. However, PDRN alone showed a more consistent and potent effect compared with its combinations with red or infrared light. The combined treatments did not potentiate the effects and, in some cases, reduced the cellular response. Among the light sources, none surpassed the effects of PDRN, with red light being less effective for COL3A expression and infrared light less effective for elastin expression.