Análise histológica do processo cicatricial de queimaduras de 2° grau induzida por membrana de borracha natural com copaíba em ratos Wistar

Abstract

Burn injuries represent a public health problem that lead to damage of body tissues causing cell death. The healing process involves a cascade of cellular, molecular and biochemical events. To date, there is no standard dressing for treating this type of injury. Therefore, a dressing that favors the healing process was developed from a natural rubber membrane associated with Copaiba obongifolia (copaiba) extract. The aim was to analyze the process of skin tissue remodeling in Wistar rats subjected to a second-degree burn and treated with a natural rubber membrane and copaiba. Fifteen male Wistar rats were divided into four groups: unburned (SQ), burned (Q), treated with silver sulfadiazine (SS) and treated with natural rubber membrane with copaiba (BNC). The animals were anaesthetized and, in the dorsal region, had a 2nd degree burn induced with a metal plate heated for 10 seconds. The Q group received no treatment, the SS group received daily applications of the ointment in the area of the injury, while the BNC group had the membrane containing 75mg/mL of copaiba extract and natural rubber fixed immediately after the burn. After 10 days of treatment, the animals were killed by decapitation under anesthesia. Skin tissue was biopsied for histopathological study using hematoxylin eosin (HE) and Mason's Trichrome (MS) staining. The analyses were carried out using an Eclipse E200-Nikon optical microscope (Nikon, Japan) and the images were captured using a 5.0 MP digital camera system (Opton, Brazil). The data was analyzed by analysis of variance (ANOVA) followed by Tukey's multiple comparison test, and the data is expressed as mean ± standard deviation (SD), with p-values < 0.05 being considered significant. Histopathological analysis using HE staining showed the presence of inflammatory infiltrates in the BNC group. In the BNC group, it was possible to observe an increased structural organization of the dermis when compared to the Q group, which showed disorder and a denser appearance. The SS group showed an increase in dermis thickness when compared to the Q group, but there were no differences in relation to the BNC group. Analysis of the slides stained using the MS method showed a similar degree of collagen deposition, with no difference between the groups analyzed. Thus, the BNC group's histological findings show evidence of improved healing.