Polarized Light Improves Cutaneous Healing on Diabetic Rats

摘要

The aim of this study was to evaluate the healing of 3~(rd) degree burn on diabetic rats submitted or not to treatment with Polarized Light. Diabetes mellitus (Streptozotocin, 60mg/kg) was induced on 45 male Wistar albinus rats and a third degree burn (1.5X1.5cm) was created in the dorsum of each animal under general anesthesia. After a regular quarantine period, the animals were randomly distributed into three groups as follows: G1:control (no treatment, n =15); G2: Polarized Light (λ=400-2000nm, 20J/cm~2) and G3: Polarized Light (λ=400-2000nm, 40J/cm~2). The phototherapy performed on group G2 was Polarized Light dose 20J/cm~2 and G3 was Polarized Light dose 40J/cm~2 (Bioptron, λ4002000 nm, 40mW; 2.4J/cm~2 per minute; Φ± 5.5 cm; Bioptron AG, Monchaltorf, Switzerland). The phototherapy started immediately post-burning and was repeated daily until the day before the animal death. The energy was applied transcutaneously respecting the focal distance of 10cm as recommended by the manufacturer. The dose was 20 or 40J/cm~2 (4min 15s or 8min.and 30s). At each time point chosen (7, 14, and 21 days post-burning) and following macroscopic examination, each animal was killed by an overdose of general anesthesia. Slides were stained with FIE, Sirius Red, and CK AE1/AE3 antibody. Qualitative and semi-quantitative analyses were performed under light microscopy. The animals submitted to phototherapy (20J/cm~2) showed significant differences on regards revascularization and epithelialization. The use of 20J/cm~2 was effective on improving the healing of third degree buns on diabetic animals at both early and late stages of the repair.