Efeito de filmes de colágeno contendo ácido úsnico em queimaduras utilizando modelo suíno

• Autor(a) principal: Nunes, Paula Santos
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3555
• topic: Queimadura; Suínos; Membrana de gelatina; Lipossomas; Ácido úsnico; Burn; Pigs; Gelatin membrane; Liposomes; Usnic acid; CNPQ::CIENCIAS DA SAUDE

The search for products to treat wounds caused by burns is mainly increasing. Several products are developed and marketed with the purpose of act accelerating the scar dynamics, such as topical agents, solutions, grafts, and interactive dressings and biofilms. The gelatin has been one of the most studied materials for this purpose because it shows cellular architecture suitable to act as support in the construction of new tissues as well, allows the incorporation of active substances in its protein structure. The usnic acid (UA), a secondary metabolite of lichens, has shown promising biological properties for the treatment of wounds, such as antimicrobial and anti-inflammatory activities. However, it is a metabolite waterinsoluble and for its incorporation into gelatin membranes, it is necessary the use of liposomes, which enable the incorporation of insoluble drugs for subsequent controlled release. In this perspective, the aim of this study was to evaluate the effect of gelatin membranes containing usnic acid/liposome about scar repair of burns in pigs. The biological assay was realized with nine (09) male pigs, 03 animals in each group forming three groups which were sacrificed 8, 18 and 30 days after the induction of the burn for removal of specimens and development of histological slides. Three burns were made on the dorsum of each animal, which were coated with three products: silver sulfadiazine ointment (group SDZ); Duoderme ® (group GDU) and gelatin films containing usnic acid/liposome (group UAL). The results of the macroscopic examination showed progressive reduction of the injured area over time for the three experimental groups, furthermore, there was no clinical signs of secondary infections. In the analysis of the average rate of contraction of wounds no statistically significant difference between the rates of decline observed for animals in any group and time periods analyzed (p> 0,05). In the microscopy in eight days, all three groups showed hydropic degeneration of the epithelium, with intense neutrophilic infiltration. The reaction of granulation observed in the central region of the injured group SDZ was more immature than in groups GDU and UAL. In 18 days, the neo-formation epidermal, although partial in the three groups showed quite incipient in SDZ compared to groups GDU and UAL. The inflammatory reaction was reduced in all groups, but the reaction of granulation was more immature in group SDZ, in relation to the reaction of exuberant granulation, richly with cells evidenced in groups GDU and UAL. In 30 days, the reaction of granulation, showed to be more extensive in group SDZ, opposing the restricted reaction of granulation observed in groups GDU and UAL, present only in the region below the epithelium. In group SDZ also observed the presence of inflammatory infiltrate involved in the reaction of granulation. In the analysis of collagen by picrosirius there was a gradual substitution of the fibers of collagen type III to type I, and the improvement in the density of collagen in all groups, but in UAL compared to groups and SDZ GDU it was observed a faster substitution of collagen fibers, as well as improvement in the density of collagen. Therefore it is concluded that the UAL group promoted the development and maturation of granulation reaction, scar repair comparable to duoDermeÒ and better than the sulfadiazine silver ointment, as well as increase of collagen deposition compared to the other two groups.