Preparação caracterização de membrana de borracha natural associado ao extrato de Copaifera oblongifolia para aplicações médicas

• Ano de defesa: 2020
• Autor(a) principal: Marques Junior, Jair
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Instituto de Ciências Exatas e da Terra (ICET) – Araguaia; UFMT CUA - Araguaia; Programa de Pós-Graduação em Ciência de Materiais
• Palavras-chave em Português: Copaíba; Seringueira; Lesão de pele; CNPQ::CIENCIAS EXATAS E DA TERRA; Rubber tree; Skin lesion
• Link de acesso: http://ri.ufmt.br/handle/1/4888

Skin substitutes have been considered useful in the treatment of some types of skin lesions, as they reduce the frequency of dressing changes. However, these materials are expensive and not fully effective. The absence of an ideal dressing for the treatment of various types of lesions results in the need for further studies that seek alternative biological materials for the treatment of wounds. The natural rubber (latex) extracted from the rubber tree Hevea brasiliensis is widely used in the industry and has shown promise in biomedical applications, as it has biocompatibility and the ability to induce angiogenesis. The fruits of Copaifera oblongifolia (copaíba) have a great antioxidant, anti-inflammatory and healing potential, constituted by the presence of secondary metabolites of pharmacological value contained in its extract, which makes this plant have an important potential in the healing activity of the skin. Thus, this work aimed to prepare and characterize natural rubber membranes associated with the hydroalcoholic extract of Copaifera oblongifolia for the development of a dressing for application to skin lesions. Natural rubber (Hevea braziliensis) was collected from a rural property located in the municipality of Ponta do Araguaia by the process of spiral bleeding. The copaiba extract was prepared using 500,14g of dried fruits using the technique of extraction by rotation at a temperature of 40°C until obtaining the constant weight of 74,52g of extract; after this process, it was analyzed by phytochemical screening, antioxidant activity (DPPH radical) and cytotoxicity action. The membranes were made in two forms, called homogeneous and layered, using three different concentrations of the extract (25mg/3ml, 50mg/3ml and 75mg/3ml) and polymerized at 40°C; subsequently submitted to analyzes of mechanical resistance, release test and antioxidant activity, wetting test, atomic force microscopy (AFM), scanning microscopy (SEM) and infrared spectroscopy (FT-IR). The results from the phytochemical analysis of the fruits of Copaifera oblongifolia revealed the presence of several categories of polyphenols. It had a significant antioxidant action against the DPPH· radical with a percentage of antioxidant activity (AA%) of 89,57% in the concentration 500.0 μg.mL-1. In the cytotoxicity test, it demonstrated an LD50 = 314,64 mg/kg, which proved to be non-toxic at concentrations of 25mg/3ml, 50mg/3ml and 75mg/3ml. The release profile and antioxidant activity showed that the homogeneous membrane released 7,526 μg.mL-1 whereas the membrane in layer 9,9627 μg.mL-1 of extract in solution and the percentage of % AA were 176,84% and 178,92%, respectively. There was an increase in mechanical resistance due to the increase in Young's module of homogeneous membranes and layered membranes, as well as a change in the topography of the membranes through microscopic analysis and FT-IR results showed that there was no interaction between the membrane and extract. Relating the values found in this study with data obtained in the literature, it demonstrated that there is compatibility between the extract of the fruits of copaiba and natural rubber, and through this fact it was concluded that the natural rubber membrane in association with the antioxidant properties of the extract proved to be promising for the development of a dressing to treat skin lesions.