SÍNTESE DE NANOESFERAS POLIMÉRICAS MAGNÉTICAS APLICADAS NA ENCAPSULAÇÃO E LIBERAÇÃO CONTROLADA DO ACETOXI DMU

Abstract

The magnetic polymer nanospheres have great application potential in the biomedicine field. Obtain nanoparticles (NPs) starting from the chitosan derivative combination with cobalt ferrite (CoFe2O4) MNPs and with Acetoxy DMU drug can become nanostructured systems promising for release of this drug in desired sites. In this work, the CoFe2O4 pure NPs and oleic acid (OA) coated, were synthesized by the chemical coprecipitation method, influence of temperature ando of the stirring rate have been analyzed. The material was characterized by X-ray diffraction techniques (XRD), dynamic light scattering (DLS), zeta potential (ZP), infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG / DTA), and magnetization measurements (VSM and ZFC-FC). The results confirmed the obtanied CoFe2O4, and that temperature variation influence the coating of the MNPs by AO. The samples presented moderate magnetization and the average size of the coated particles analyzed by DLS were lower than expected for CoFe2O4 (21 a 57 nm). The active principle Acetoxy DMU was synthesized Heck-Matsuda reaction and characterized in próton nuclear magnetic resonance (1H NMR), which proved the characteristic groups and purity of the obtained Acetoxy DMU molecule. To use the chitosan as a coating polymer, was carried out chemical modification surface by insertion of carboxymethyl groups and benzyl group giving a amphiphilic polymer. The obtained derivatives, carboxymethylchitosan and carboxymethylchitosan-bz, was characterized by conductimetric and potentiometric titration techniques, infrared spectroscopy (FTIR), próton nuclear magnetic resonance (1H NMR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG / DTA). Accordance with the obtained results, the carboxymethyl groups was insertion in the molecule, the carboxymethylchitosan formed (hydrophilic parts), with of carboxymethylation degree (GC) 22,1% and 44,1%. Was also insertion confirmed of the bezyl groups forming the carboxymethylchitosan-bz (hydrophobic parts), with substitution degree (GS) between 40% to 66%. At the end of work was conducted validation of the analytical method for the Acetoxi DMU and synthesized polymer nanosphere and magnetic polymer nanosphere by the emulsion diffusion of the solvent method. The obtained material characterized by dynamic light scattering (DLS), zeta potential (ZP). According to obtained results, it can be conclude that the CoFe2O4 NPs were inserted the nanospheres inside. The magnetic polymeric nanospheres showed average size between 332 e 482 nm higher to polymeric nanospheres, which showed average size between 134 and 320 nm. Order to calculate the drug encapsulation efficiency (EE %) was used in the spectrophotometric technique UV-Vis. The obtained results stood at between 16.0% and 96.1%, by showing that the best encapsulation has occurred with the carboxymethylchitosan polymer in the presence of the CoFe2O4. These obtained nanostructures it can apply in drug targeting to specific targets Acetoxy DMU, be for combat or control of oncological diseases.