Síntese e caracterização de nanocarreadores lipídicos multifuncionais contendo magnetita e oncocalixona-a

Abstract

This work describes the development and characterization of Magnetic Solid Lipid Nanoparticles (MSLN) for application in magnetic hyperthermia and controlled release of oncocalyxone A. Ferrofluid was obtained by coprecipitation method of the salts Fe (II) and Fe (III) in alkaline medium, whose nature (magnetite-Fe3O4) was confirmed by X-ray Diffraction (XRD). For the optimization of systems, was necessary the development of formulations with use of lipids trilaurin, tricaprin, tricaprylin, oleic acid and carnauba wax. It was possible to identify the best systems through the techniques of X-ray diffraction, Thermogravimetric Analysis (TGA), Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). The magnetic systems MSLN3 and MSLN4, respectively constituted by mixtures of trilaurin-tricaprin and trilaurintricaprylin, have been successfully obtained by emulsion solvent evaporation method. Since the MSLN5 system containing carnauba wax as lipid matrix was obtained by the melt emulsification method. The average diameter (176.3 ± 8 nm for MSLN3, 177.8 ± 9 nm for MSLN4 and 217.5 ± 5 nm for MSLN5) and polydispersity index (0.237 ± 0.1 to MSLN3, 0.180 ± 0.13 to MSLN4 and 0.148 ± 0.12 to MSLN5) were obtained by DLS. SEM micrographs allowed a morphological analysis of the material, revealing an irregularly acquired by nanoparticles MSLN3 and MSLN4. The Transmission Electron Microscopy (TEM) images and SEM also allowed to evaluate the acquired form the nanoparticle MSLN5, which had a predominantly spherical morphology. The values for the saturation magnetization obtained from Vibrating Sample Magnetometer (VSM) were 70 emu/g (Fe3O4@OA), 2.2 emu/g (MSLN3) and 2.8 emu/g (MSLN4). The MSLN's developed were subjected to magnetic hyperthermia studies and show a potential application for this purpose. Magnetic hyperthermia studies were performed in a fixed field (200 Oe) for all samples and for MSLN3, MLSN4 and MSLN5, applied two frequencies: 688 KHz (where MSLN3 and MSLN4 reached a temperature increase of 13, 14.4 and 8.72 °C respectively) and 869 KHz (where MSLN3, MSLN4 and MSLN5 reached a temperature increase of 19.3, 22 and 13.05 °C respectively). In vitro assays in the absence of the magnetic field showed that the formulations MSLN were able to modify the release profile, delaying the release of the active function of time, where the rate of release after 72h testing were 73% (MSLN3), 55% (MSLN4) and 49% (MSLN5). In addition, MSLN3 and MSLN4 showed low cytotoxicity in vitro against human neutrophils. Thus, the magnetic solid lipid nanoparticles open new perspectives for biomedical applications through the synergism between the therapeutic action of bioactive compounds and hyperthermia properties from iron oxide nanoparticles.