Effects of laser irradiation (670-nm InGaP and 830-nm GaAlAs) on burn of second-degree in rats

Abstract

This study investigated the effects of 670-nm indium gallium phosphide (InGaP) and 830-nm gallium aluminum arsenide (GaAlAs) laser therapy on second-degree burns induced on the back of Wistar rats. Sixty-three male Wistar rats were anesthetized, and second-degree burns were made on their back. The animals were then divided randomly into three groups: control (C), animals treated with 670-nm InGaP laser (LIn), and animals treated with 830-nm GaAlAs laser (LGa). The wound areas were removed after 2, 6, 10, 14, and 18 days of treatment and submitted to structural and morphometric analysis. The following parameters were studied: total number of granulocytes and fibroblasts, number of newly formed blood vessels, and percentage of birefringent collagen fibers in the repair area. Morphometric analysis showed that different lasers 670-nm InGaP and 830-nm GaAlAs reduced the number of granulocytes and an increase of newly formed vessels in radiated lesions. The 670-nm InGaP laser therapy was more effective in increasing the number of fibroblasts. The different treatments modified the expression of VEGF and TGF-β1, when compared with lesions not irradiated. The different types of light sources showed similar effects, improved the healing of second-degree burns and can help for treating this type of injury. Despite the large number of studies with LLTI application in second-degree burns, there is still divergence about the best irradiation parameters to be used. Further studies are needed for developing a protocol effective in treating this type of injury.

Anti-inflammatory effects of low-level laser in burn wound models in rats

“…Bayat et al [33] examined the effects of low-level helium-neon laser on rats that had received third-degree burns and reported a significant increase in total quantity of mast cells and newly created epidermal cells at the burn lesion site in the group treated with laser therapy compared with the control group. Chiarotto et al [16] evaluated the effects of InGaP (670-nm) and GaAlAs (830-nm) on second-degree burns in rats and reported similar results of decrease in granulocyte numbers, increase in angiogenesis and fibroblast proliferation, which were reported to expedite the healing process of the second-degree burns after laser therapy. We found similar results of a reduced inflammatory period, fibroblast proliferation and increases in granulation tissue resulting in the promotion of third-degree burn wound healing after laser therapy [34].…”

“…Deep penetration of low level laser photons into the body through the skin, nerves, tendons, muscles, ligaments, and even bones can occur to address the painful and injured areas [15]. Thus, the use of low intensity laser therapy is a frequently recommended physical therapy method used for treating burn wounds [16,17]. Although the beneficial effects of laser therapeutic intervention on the burn wound healing process has been reported, information about the interaction of therapeutic laser on burn wounds are insufficient.…”

Casearia sylvestris Improved Cutaneous Burn Repair in Diabetic Rats

“…The burn (2nd degree) was performed in their dorsum skin by applying an aluminum metal plate (2.0 cm in diameter), adapted to an apparatus that maintains the constant temperature of 120 ºC, for 20 seconds [5]. To ensure the same pattern of burns in all animals, a support was used to hold the aluminum plate with the same pressure on the skin of the animals' backs.…”

“…The repair of burned tissues involves complex biological and molecular events mediated by cytokines and growth factors, with interaction and proliferation of different cell types as well as collagen deposition and ECM [5]. Burn in patients with diabetes is a significant clinical problem, being a major challenge for professionals and the healthcare system [6].…”

Alternative animal model for studies of total skin thickness burns

“…Subsequently, the process of burning the skin of the animal was started through a 3 cm diameter circular aluminum plate coupled to a soldering iron, with a total weight of 190 grams [8][9][10] (Figure 1), heated at a temperature of 150 °C, controlled with the aid of a thermostat ( Figure 2) [10][11][12] . The plate was pressed in the dorsal region of the animals in three different times, being for G5: 5 seconds, G10: 10 seconds and G15: 15 seconds.…”