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

• Published in: Lasers in medical science 2014-09, Vol.29 (5), p.1685-1693
• Main Authors: Chiarotto, Gabriela Bortolança, Neves, Lia Mara Grosso, Esquisatto, Marcelo Augusto Marreto, do Amaral, Maria Esméria Corezola, dos Santos, Gláucia Maria Tech, Mendonça, Fernanda Aparecida Sampaio
• Format: Article
• Language: English
• Subjects: Animals; Birefringence; Blood Vessels - pathology; Burn treatment; Burns - pathology; Burns - therapy; Cell Count; Dentistry; Fibroblasts - pathology; Gallium - chemistry; Indium - chemistry; Lasers; Lasers, Semiconductor; Low-Level Light Therapy; Male; Medicine; Medicine & Public Health; Optical Devices; Optics; Original Article; Pancreatitis-Associated Proteins; Phosphines - chemistry; Photonics; Quantum Optics; Rats, Wistar; Rodents; Skin - pathology; Staining and Labeling; Transforming Growth Factor beta1 - metabolism; Vascular Endothelial Growth Factor A - metabolism
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-014-1573-9

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.