RESUMO
In this research work, DEXTRAN- and polyethylene glycol (PEG)-coated iron-oxide superparamagnetic nanoparticles were synthetized and their cytotoxicity and biodistribution assessed. Well-crystalline hydrophobic Fe3 O4 SPIONs were formed by a thermal decomposition process with d = 18 nm and σ = 2 nm; finally, the character of SPIONs was changed to hydrophilic by a post-synthesis procedure with the functionalization of the SPIONs with PEG or DEXTRAN. The nanoparticles present high saturation magnetization and superparamagnetic behavior at room temperature, and the hydrodynamic diameters of DEXTRAN- and PEG-coated SPIONs were measured as 170 and 120 nm, respectively. PEG- and DEXTRAN-coated SPIONs have a Specific Power Absorption SPA of 320 and 400 W/g, respectively, in an ac magnetic field with amplitude of 13 kA/m and frequency of 256 kHz. In vitro studies using VERO and MDCK cell lineages were performed to study the cytotoxicity and cell uptake of the SPIONs. For both cell lineages, PEG- and DEXTRAN-coated nanoparticles presented high cell viability for concentrations as high as 200 µg/mL. In vivo studies were conducted using BALB/c mice inoculating the SPIONs intravenously and exposing them to the presence of an external magnet located over the tumour. It was observed that the amount of PEG-coated SPIONs in the tumor increased by up to 160% when using the external permanent magnetic as opposed to those animals that were not exposed to the external magnetic field.
Assuntos
Dextranos/farmacocinética , Compostos Férricos/farmacocinética , Campos Magnéticos , Nanopartículas , Animais , Chlorocebus aethiops , Dextranos/administração & dosagem , Dextranos/toxicidade , Cães , Portadores de Fármacos , Avaliação Pré-Clínica de Medicamentos , Feminino , Compostos Férricos/administração & dosagem , Compostos Férricos/toxicidade , Técnicas In Vitro , Injeções Intravenosas , Fígado/metabolismo , Pulmão/metabolismo , Células Madin Darby de Rim Canino , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/toxicidade , Neoplasias Mamárias Experimentais/metabolismo , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/administração & dosagem , Nanopartículas/toxicidade , Polietilenoglicóis , Pele/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Distribuição Tecidual , Células VeroRESUMO
We propose a new method for determining the quantity of superparamagnetic iron oxide nanoparticles (Fe3O4, SPIONs) embedded in animal tissue using magnetization measurements. With this method, the smallest detectable quantity of magnetite nanoparticles in a tissue sample is -1 microg. We showed that this method has proved being efficient. In this study, we focused in determining the quantity of SPION confined in lung and liver tissue of mice injected with -13 nm magnetite superparamagnetic nanoparticles. Furthermore, the method allowed us to detect the magnetite nanoparticles present in animal tissues without letting the natural iron ions present in the tissue or blood interfere with the measurements.