Activity of low level laser therapy on burning wounds in diabetic rats

Abstract

OBJECTIVE: This study evaluated the effects of low level laser (LLL) therapy in the healing of third degree burning wounds in diabetic and non-diabetic Wistar rats. METHODS: The diabetes was experimentally induced with streptozotocine 14 days before the burning injury induction. The rats suffered the induction of third-degree burning injury and were divided into four groups as follows: control group; non-diabetic treated group; diabetic group; diabetic treated group. All animals received occlusive bandages during the experimental days. The treated animals received the following treatment in alternate days: diode GaAlAs laser (650 nm/ 12 mW), fluency of 3 J/cm2 until the 7th experimental day followed by 6 J/cm2 from the 7th day until the euthanasia day. The burning wounds were morphometrically, macroscopically and microscopically evaluated at 3, 7, 14, 21 and 30 days after the induction. RESULTS: The wound contraction was significantly higher in all experimental days in treated groups when compared to the diabetic and non-diabetic control groups. Microscopically, there was a significant increase in angiogenesis and in fibrogenesis during the proliferative stage in the treated groups. CONCLUSION: Therefore, we conclude that LLL therapy favored the tissue healing process with 3 J/cm2 dosage for the inflammatory stage and with 6 J/cm2 dosage for the proliferative and remodeling ones, accelerating the burning wound contraction and improving the healing process.