Comparação entre o efeito do uso de diclofenaco de sódio e o laser de baixa potência (830nm) no processo de cicatrização em pele de ratos: aspectos biomecânicos e histológicos

Abstract

The skin is a coating tissue which undergoes permanent environmental action, often in aggressive forms, causing damage to this tissue. Generally, in the repair process structural changes occur which progress to the development of a scar. In this case the tissue may present morphological changes that interfere with its mechanical properties and this repair process produces a tissue with different properties than of the original tissue. Therefore, the use of therapies that favor this repair is important to seek a better scar quality. Low-level laser therapy appears as a resource used in the modulation of the inflammatory process helping the skin repair process. The objective of this study was evaluate the effect of low level laser (830nm) with 100 mW of potency us ing 1J or 3J of energy comparing to the effect of the topical sodium diclofenac on the repair process of the rat´s skin after induction of injury, analyzing the biomechanical behavior and histological changes of skin, 28 days after the harmful process. Male Wistar rats between 150g to 200g, 3 months old were used. The animals were anesthetized with association of xylazine hydrochloride and ketamine (90mg / kg and 10mg / kg, respectively, intraperitoneal injection). Once anesthetizd, 2 lesions were performed using a surgical scalpel at the dorsal area of the animal. The animals were divided into 5 groups of 7 animals: control (CTL), untreated scar (NT), scar + anti-inflammatory (DIC), scar + 1J laser (L1J) and scar + 3J laser (L3J). The pharmacological treatment and laser therapy were performed immediately after lesion induction and maintained daily irradiation until day 7. After 28 days, the animals were euthanized with an overdose of the same anesthetic and the tissue was immediately removed for histological analysis and traction trials. Results: Both the NT and group DIC showed a reduction of mechanical properties and alterations in histology analysis. L1J group showed significant improvement in mechanical properties and histological organization. We conclude that laser therapy improves certain mechanical properties of skin in this lesion model. However, more studies should be conducted to understand the proportion and organization of collagen fibers I and III biochemicaly. Either the study can be longer and evaluate the scars after the remodeling process.