ALBERT

Description: Film-forming emulsions and films, prepared by incorporating different concentrations of clove essential oil (CEO) and melaleuca essential oil (MEO) into chitosan (CS) were obtained and their properties were evaluated. Film-forming emulsions were characterized in terms of qualitative assessment, hydrogen potential and in vitro antibacterial activity, that was carried by the agar diffusion method, and the growth inhibition effects were tested on the Gram-positive microorganism of Staphylococcus aureus, Gram-negative microorganisms of Escherichia coli, and against isolated fungi such as Candida albicans. In order to study the impact of the incorporation of CEO and MEO into the CS matrix, the appearance and thickness of the films were evaluated. Furthermore, Fourier transform infrared spectroscopy (FTIR), contact angle measurements, a swelling test, scanning electron microscopy and a tensile test were carried out. Results showed that the film-forming emulsions had translucent aspect with cloudy milky appearance and showed antimicrobial properties. The CEO had the highest inhibition against the three strains studied. As regards the films’ properties, the coloration of the films was affected by the type and concentration of bioactive used. The chitosan/CEO films showed an intense yellowish coloration while the chitosan/MEO films presented a slightly yellowish coloration, but in general, all chitosan/EOs films presented good transparency in visible light besides flexibility, mechanical resistance when touched, smaller thicknesses than the dermis and higher wettability than chitosan films, in both distilled water and phosphate-buffered saline (PBS). The interactions between the chitosan and EOs were confirmed by. The chitosan/EOs films presented morphologies with rough appearance and with EOs droplets in varying shapes and sizes, well distributed along the surface of the films, and the tensile properties were compatible to be applied as wound dressings. These results revealed that the CEO and MEO have a good potential to be incorporated into chitosan to make films for wound-healing applications.

Description: The aim of this study was to prepare chitosan (CS) filaments incorporated with N-acetyl-D-Glucosamine (GlcNAc), using the wet spinning method, in order to combine the GlcNAc pharmacological properties with the CS biological properties for use as absorbable suture materials. The filaments were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), uniaxial tensile testing, in vitro biodegradation, and through in vitro drug release and cytotoxicity studies. It was observed that the addition of GlcNAc did not alter the morphology of the filaments. The CS and CS/GlcNAc filaments presented diameters 145 µm and 148 µm, respectively, and the surfaces were homogeneous. Although the mechanical resistance of the chitosan filaments decreased with the incorporation of the GlcNAc drug, this property was greater than the mean values indicated in the U.S. Pharmacopeia (1.7 N) for suture number 6-0 (filament diameter of 100–149 μm). The biodegradation of the CS filaments was accelerated by the addition of GlcNAc. After 35 days, the CS/GlcNAc filaments degradability was at its total, and for the CS filaments it was acquired in 49 days. The in vitro kinetic of the release process was of the zero-order and Hopfenberg models, controlled by both diffusion and erosion process. The in vitro cytotoxicity data of the CS and CS/GlcNAc filaments toward L929 cells showed that these filaments are nontoxic to these cells. Thus, the GlcNAc-loaded CS filaments might be promising as absorbable suture materials. In addition, this medical device may be able to enhance healing processes, relieve pain, and minimize infection at the surgery site due the prolonged release of GlcNAc.