Effect of Low-Level Laser Therapy (660 nm) on Angiogenesis in Wound Healing: A Immunohistochemical Study in a Rodent Model

Abstract

The aim of the present investigation was to evaluate the angiogenesis on dorsal cutaneous wounds in a rodent model treated with λ660 nm laser light. New vessel formation is a multistep process involving vessel sprouting, endothelial cell migration, proliferation and tube formation. Although several in vivo studies have shown that laser phototherapy influences tissue repair, a fully understanding of angiogenesis mechanisms are not yet known. Twenty-four young adult male Wistar rats weighing between 200 and 250 g were used. Under general anesthesia, one excisional wound was created on the dorsum of each animal and they were randomly distributed into two groups: one control and one treated with laser (λ660 nm, 16 mW, 10 J/cm2). Each group was subdivided into three subgroups according to the animal death timing (2, 4 and 6 days). Laser irradiation started immediately after surgery and was repeated every other day during the experiment and marked with Sirius Red, specific for collagen, and immunomarked with anti-TGF-β and anti-von Willebrand factor. Marked sections underwent histological analysis by light microscopy and the mean area of the wound of each animal was calculated and analyzed by ANOVA and Tukey's test (α=0.05). Although at some death periods, collagen expression and number of blood vessels on irradiated animals were higher than in the control ones, no significant differences were found at any time in relation to TGF-β expression (p>0.05). It was concluded that laser treatment (λ660 nm) contributed to increase angiogenesis.

Comparative effects of two different doses of low‐level laser therapy on wound healing third‐degree burns in rats

“…Firstly, an increase in cellular ATP production which happens due the stimulus to the electron transport chain that is inside the mitochondria is observed. Immediately afterwards, there is an increase in DNA and RNA synthesis, which then acts directly on the cell cycle regulation and favors protein synthesis, proliferation cell (Avci et al, 2013;Karu, 2010;Novaes et al, 2014;Renno et al, 2009), the angiogenesis process (Bossini et al, 2009;Colombo et al, 2013), and the action of myofibroblasts (Dantas et al, 2011;Medrado et al, 2003).…”

Effect of Low-Level Laser Therapy and Ultraviolet-C Irradiation on Partial-Thickness Burn Wound Healing: A Randomized Controlled Trial

“…Firstly, an increase in cellular ATP production which happens due the stimulus to the electron transport chain that is inside the mitochondria is observed. Immediately afterwards, there is an increase in DNA and RNA synthesis, which then acts directly on the cell cycle regulation and favors protein synthesis, proliferation cell [10- 12,31], the angiogenesis process [32], and the action of myofibroblasts [14]. Among the obtained therapeutic effects, reduction of edema, decrease tissue inflammation and stimulus to collagen synthesis may be highlighted [12,[33][34][35].…”

Comparação do laser e do led no processo de cicatrização em feridas cutâneas: uma revisão

“…Oliveira Sampaio et al 19 [27][28][29] e o LED 15,16,25 nas faixas espectrais vermelha e infra-vermelha podem aumentar a vasodilatação e a microcirculação local, resultando no aumento do aporte de oxigênio e nutrientes na lesão cutânea. Além disso, também se observou que o LED no comprimento de onda verde foi capaz de estimular a angiogênese significativamente.…”