Elaboração de filmes poliméricos com adição de óleo de copaíba (Copaifera langsdorffii Desf.) para aplicações em bioprodutos

Abstract

The development of biodegradable plastics has gained prominence in scientific research

as a sustainable alternative to petroleum-based products, which, because they are non- degradable, generate serious environmental impacts when disposed of improperly.

Among the raw materials used in the production of these biopolymers, alginate, pectin and starch extracted from the mesocarp of the babassu coconut stand out, as they have desirable properties such as high solubility, low mechanical resistance, biodegradability and absence of toxicity. The incorporation of oils emerges as a promising strategy to confer bioactivity to films, with special interest in accelerating the healing process of skin lesions. In this context, this work aimed to develop a bioactive and biodegradable film based on copaiba oil (Copaifera langsdorffii Desf.) and sodium alginate with biological potential. The production of biopolymers was carried out through the casting method, using different formulations containing glycerol as plasticizer and calcium chloride dihydrate as a crosslinking agent. A mixture design (Mixture Designs and Triangular Surfaces) was used, considering the following response variables: moisture, water solubility, thickness, and water vapor permeability (PVA). The 14 formulations tested showed the following ranges of variation: moisture between 7.87% and 48.87%, solubility between 15.38% and 93.13%, thickness from 0.060 to 0.165 mm and PVA from 1.784 to 8.018 g·mm/m2·dia·kPa. Based on the results obtained, five formulations (tests 5, 8, 9, 10 and 11) were selected for their superior performance in initial analyses. These formulations were subjected to complementary characterizations, including optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), evaluation of antioxidant potential, and antibacterial activity tests. The films showed behavior compatible with what was expected: the SEM analysis revealed the presence of crystals, while the XRD showed well-defined crystalline peaks at the characteristic peaks 31.88°, 45.49°, 56.52° and 66.26°. FTIR spectroscopy confirmed the presence of bioactive compounds typical of Copaifera langsdorffii Desf., such as sesquiterpenes and caryophyllenes. In the antibacterial activity assay, the results were considered satisfactory. Despite the absence of inhibition against the strains of Pseudomonas aeruginosa and Bacillus cereus, Copaifera langsdorffii Desf. It showed excellent results, especially in formulations 5, 8 and 11, which stood out in free radical inhibition (DPPH) tests. In addition, these formulations showed good results against the Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis strains. In view of the results obtained, it is clear that films based on biopolymers enriched with Copaifera langsdorffii Desf. They have promising potential for application in biodegradable dressings with bioactive action. The addition of other active compounds may further increase the therapeutic efficacy of these materials, whose data demonstrate alignment and competitiveness with the results available in the literature.