Photobiomodulation therapy action in wound repair skin induced in aged rats old: time course of biomarkers inflammatory and repair

Abstract

Previous studies have discussed an inverse correlation between age and wound healing, because it relates to the association of aging with a gradual decrease in healing capacity. Treatment with photobiomodulation therapy (PBMT) improves wound healing by inducing increases in mitotic activity, numbers of fibroblasts, collagen synthesis, and neovascularization. Therefore, this study aimed to evaluate the effects of PBMT in cutaneous wound healing in aged rats. A punch biopsy of 8 mm in diameter was performed to produce a skin wound. The study included 45 male rats, of which 15 were young (30 days) and 30 were elderly (500 days). The 45 animals were distributed into 3 experimental groups, which were subjected to skin wounds and 1 aged group received PBMT, with a 30-mW laser beam (power density of 1.07 W/cm), beam area of 0.028 cm, and λ660 nm produced through active phosphide Gallium-Aluminum-Indio (InGaAIP). The PBMT application took the form of a single-point transcutaneous method, with a total energy of 2 joules per wound site, energy density of 72 J/cm, and time of 1 min and 7 s. Analysis was performed to verify the effect of PBMT on the quantity of collagen I and III, metalloproteinase 3 and 9 (MMP-3 and MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2) and of vascular endothelial growth factor (VEGF) at the wound site by immunohistochemistry, cytokine-induced neutrophil chemoattractant (CINC)-1, by enzyme-linked immunosorbent assay (ELISA) and interleukin (IL)-6 real-time polymerase chain reaction (RT-PCR). That we conclude LLLT is effective in the modulation of inflammatory mediators IL-6, CINC-1, VEGF, MMP-3, MMP-9 and TIMP-2 as well as increased collagen production in aged animals during different phases of the tissue regeneration process. However, the effects of PBMT obtained in the aged animals (aged LLLT group) suggest that new dosimetries should be tested to achieve better results.

Effect of gallium arsenide low-level laser therapy on the inflammatory phase of skin wound healing in rats

“…The induction of skin lesions using a 6-mm skin punch was performed successfully in all animals and helped standardize lesions of similar sizes in the experimental animals, similarly to techniques reported in previous studies (KAWALEC et al, 2004;PEREIRA et al, 2010;FIORIO et al, 2017).…”

“…There is still no consensus on the antiinflammatory activity of PBMT because previous studies have indicated a possible anti-inflammatory activity at the initial stages of the wound-healing process (MEDRADO et al, 2008;VILELA et al, 2012;, whereas other authors did not detect this activity (VIEGAS et al, 2007). There is also the report of the modulation of inflammatory mediators (FIORIO et al, 2017). Our results indicate that the absolute number of leukocytes and the score of the semi-quantitative histopathological evaluation (i.e., polymorphonuclear infiltration) were lower in the TG than in the CG; however, these differences were not significant and consequently did not confirm the anti-inflammatory activity of GaAs PBMT.…”

“…The low cost of the equipment combined with promising results has generated great interest among researchers in using this technique for the modulation of tissue repair. Promising results have been observed with the use of photobiomodulation therapy (PBMT) in skin wound healing, including decreased inflammatory activity (DE ARAÚJO et al, 2007), modulation of inflammatory mediators (FIORIO et al, 2017), neovascularization (LORETI et al, 2015;NOVAES et al, 2014) and faster tissue repair (REDDY; STEHNO-BITTEL;ENWEMEKA, 2001;NOVAES et al, 2014).…”

Healing Effects of Photobiomodulation on Diabetic Wounds

“…The effect of PBM in aged animals has also been shown to be effective. Fiorio et al [44] investigated PBMT (660 nm, 1.07 W/cm 2 , 72 J/cm 2 ) in cutaneous wound healing in aged rats (500 days). The study demonstrated that PBM is effective in the modulation of inflammatory mediators (IL-6, CINC-1, and VEGF) and matrix metalloproteinases and their inhibitors (MMP-3, MMP-9, and TIMP-2).…”

Estudo comparativo de diferentes protocolos de irradiação com laser de baixa potência para a reparação tecidual de excisões realizadas em dorso de ratos não diabéticos e diabéticos induzidos por estreptozotocina

“…Em pele, alguns artigos na literatura também reportam que a PBMT apresentou efeitos positivos na modulação do processo inflamatório e estimulação da proliferação celular (como células precursoras miogênicas e fibroblastos), podendo, dessa maneira, resultar em uma maior produção de colágeno, e consequentemente em uma cicatrização melhorada do tecido (118,135,166).…”