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.

Objectives: This study evaluated the wound healing activity of microcurrent application alone or in combination with topical Hypericum perforatum L. and Arnica montana L. on skin surgical incision surgically induced on the back of Wistar rats. Design: The animals were randomly divided into six groups: (1) no intervention (control group); (2) microcurrent application (10?A/2 min); (3) topical application of gel containing H. perforatum; (4) topical application of H. perforatum gel and microcurrent (10?A/2 min); (5) topical application of gel containing A. montana; (6) topical application of A. montana gel and microcurrent (10?A/2 min). Tissue samples were obtained on the 2nd, 6th and 10th days after injury and submitted to structural and morphometric analysis. Results and conclusion: Differences in wound healing were observed between treatments when compared to the control group. Microcurrent application alone or combined with H. perforatum gel or A. montana gel exerted significant effects on wound healing in this experimental model in all of the study parameters (P < 0.05) when compared to the control group with positive effects seen regarding newly formed tissue, number of newly formed blood vessels and percentage of mature collagen fibers. The morphometric data confirmed the structural findings. In conclusion, application of H. perforatum or A. montana was effective on experimental wound healing when compared to control, but significant differences in the parameters studied were only observed when these treatments were combined with microcurrent application.

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This study evaluated the effects of microcurrent stimulation (10 µA/5 min) and 904 nm GaAs laser irradiation (3 J cm −2 for 69 s/day) on excisional lesions created in the calvaria bone of Wistar rats. The results showed significant responses in the reduction of inflammatory cells and an increase in the number of new blood vessels, number of fibroblasts and deposition of birefringent collagen fibers when these data were compared with those of samples of the untreated lesions. Both applications, microcurrent and laser at 904 nm, favored tissue repair in the region of bone excisions during the study period and these techniques can be used as coadjuvantes in the repair of bone tissue.

This study evaluated the effects of microcurrent application and 670 nm InGaP laser irradiation on wound healing in healthy and alloxan diabetic rats. The animals were divided into eight groups: healthy control (HC); diabetic control (DC); healthy treated with microcurrent (HMC); diabetic treated with microcurrent (DMC); healthy irradiated with laser (HL); diabetic irradiated with laser (DL); healthy receiving laser and microcurrent application (HLMC) and diabetic receiving laser and microcurrent application (DLMC). Wound samples were collected on days 2, 6, 10 and 14 of treatment for structural analysis, morphometry, and Western blotting to quantify the expression of TGF-β1 and VEGF. Comparison of animals receiving laser and microcurrent therapy showed a reduction in the number of inflammatory cells in diabetic animals, as well as an increase of fibroblasts in healthy animals and of newly formed vessels in healthy and diabetic animals. Expression of TGF-β1 was increased on day 6 in all groups, especially diabetic animals. A reduction in the expression of this protein was observed on day 10 in all groups. VEGF expression was higher on day 6 in treated and control diabetic animals when compared to healthy animals. Analysis of VEGF expression in the laser-and microcurrent-treated groups on day 10 showed a decrease in diabetic animals and an increase in healthy animals. In conclusion, laser therapy and microcurrent stimulation exert beneficial effects on wound healing in both healthy and diabetic animals.

Therapies that accelerate the healing of burn injuries, improving the quality of life of the patient and reducing the cost of treatment are important. This study evaluated the effects of InGaP 670-nm laser therapy combined with a hydroalcoholic extract of Solidago chilensis leaves on burn wound healing in rats. Seventy-two rats were divided randomly into four groups: control untreated (C), treated with InGaP 670-nm laser with power density of 0.41 W/cm(2) and energy density of 4.93 J/cm(2) (L), treated with S. chilensis extract (S) and treated with S. chilensis extract and laser (LS). Second-degree burns were produced on the back of the animals with metal plate. Wound samples were collected on days 7, 14 and 21 of treatment for structural analysis, morphometry and Western blotting to quantify the expression of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF). The results showed that InGaP laser irradiation at 670 nm alone and combined with extract of S. chilensis promoted significant tissue repair responses in this experimental model, increasing the number of fibroblasts, collagen fibres and newly formed blood vessels throughout the experimental period and decreasing the number of granulocytes in burn wounds of second degree in all treated groups. Exclusive treatment of burn wounds with the hydroalcoholic extract of S. chilensis provided similar quantitative results to those seen in the untreated group throughout the experimental period. Therefore, it was observed in the L and LS groups different responses in the expression of TGF-β1 and VEGF. The application of 670-nm laser alone or combined with the extract of S. chilensis promoted favourable responses in tissue repair of second-degree burns in this experimental model.

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The treatment of burn wounds has been a challenge due to their severity and associated multiple complications, and represents a major public health problem. This study investigated the effects of 670 nm InGaP laser irradiation and microcurrent (10 µA) stimulation on the healing of second-degree burns inflicted on the back of Wistar rats. Seventy-two animals were divided into four groups: no treatment (C); animals irradiated with a 670 nm InGaP laser (L); animals receiving microcurrent stimulation (10 µA/3 min) (MC); animals receiving 670 nm InGaP laser therapy and microcurrent stimulation (10 µA/3 min) on alternate days (MCL). Wound samples were collected on days 7, 14 and 21 of treatment for structural and morphometric analysis and for Western blotting to quantify the expression of TGF-β1 and VEGF. The applied alone and alternate of laser and microcurrent reduced the number of inflammatory cells and increased the number of newly formed vessels and fibroblasts, collagen fiber content and fiber reorganization. The two treatments also favorably modified the expression of VEGF and TGF-β1, inducing angiogenesis and decreasing the inflammation time.