Avaliação da atividade antimicrobiana de membrana de borracha natural associada a nanoemulsão de óleo vegetal de copaíba e sucupira para o tratamento de queimaduras

Abstract

The skin covers approximately 2 m² of the body surface and is considered the largest organ in the human body. Due to constant contact with the external environment, this organ is often exposed to damage, such as burns. The loss of the skin barrier makes the individual susceptible to septic processes, which can lead to death. Therefore, therapeutic interventions must be implemented quickly to prevent the worsening of burns. Natural rubber biomembranes have garnered increasing interest in the biomedical field due to their biocompatibility, ability to promote tissue healing, and induce angiogenesis, as well as their potential use as a matrix to incorporate other components aimed at enhancing or developing new therapeutic effects. This study investigates the preparation, characterization, and antimicrobial evaluation of nanoemulsions formulated with copaiba oil and sucupira oil, in association with natural rubber membranes. The nanoemulsions were synthesized using ultrasonication and characterized through physicochemical stability tests and dynamic light scattering (DLS) analysis. The membranes associated with the nanoemulsions were fabricated and characterized using Fouriertransform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). After characterization, antimicrobial tests were conducted with strains of Staphylococcus aureus (gram-positive), Pseudomonas aeruginosa (gram-negative), and Candida albicans (fungus). In the experiment, nine formulations of nanoemulsions were developed, of which only the one containing 20% oil (0.6 mg/mL) demonstrated the greatest stability. In the characterization tests, no new bands of functional groups were observed when comparing the analyses of pure membranes with the samples associated with nanoemulsions, indicating homogeneous incorporation. SEM analysis revealed that the membranes exhibited uniform characteristics, with no presence of pores. Regarding the antimicrobial assay, the tests showed that the copaiba and sucupira nanoemulsions at 20% (0.6 mg/mL) exhibited activity against Staphylococcus aureus and Pseudomonas aeruginosa, while no sample demonstrated an inhibitory effect against Candida albicans. The natural rubber membranes with copaiba nanoemulsion showed sensitivity against Pseudomonas aeruginosa, while the other membranes exhibited intermediate sensitivity, inhibiting bacterial and fungal growth only in the area of contact with the inoculated plates.