Photobiomodulation and bacterial cellulose membrane in the treatment of third-degree burns in rats

Burns are injuries caused mainly by thermal trauma, which can progress to unsatisfactory results healing. This study aimed to evaluate the biomaterial (bacterial cellulose membrane) and photobiomodulation, exclusively and associated, in the treatment of third degree burns in rats. Forty male Wistar rats (±280 g) were randomly divided into four groups, with 10 animals each: control group (CG); bacterial cellulose membrane group (MG); laser group (LG) and bacterial cellulose membrane and laser group (MG + L). The burn was caused with a 1 cm² aluminum plate heated to 150 °C and pressed on the animal's back for 10 s. The treatments were started immediately after induction of injury. For to laser irradiation (660 nm, 100 mW, 25 J/cm² and energy of 1 J) on five distinct application points were used, on alternate days, a total of five sessions. After ten days of treatment the animals were euthanized for collected samples. One-way ANOVA and Tukey's tests (P < 0.05) were used. Histological analysis revealed differences regarding the healing process phase in each experimental group. MG showed the proliferative phase. The LG demonstrated greater amount of blood vessels and immune expression of VEGF. However, when the treatments were combined, the number of vessels and the immune expression of VEGF factor was lower than LG. Thus, it was concluded that both treatments proposed (biomaterial and LLLT) are good alternatives for third degree burns when applied isolated because they stimulate the healing process by acting on the modulation of the inflammatory phase and promote stimulation of angiogenesis.