The potential of nanosystems with combined magnetic and plasmonic properties for biomedical applications has been recognized. Magnetic nanoparticles can enable magnetic drug targeting and hyperthermia, while plasmonic gold nanoparticles ensure effective local heating (photothermia) using relatively low energies for gold excitation. Considering cancer therapy, the combination of magnetic and plasmonic capabilities in a single multifunctional nanosystem allows magnetic guidance and production of local heat, the latter promoting triggered drug release and synergistic cytotoxic effect in cancer cells (combined chemo/phototherapy).1 In this work, magnetic/plasmonic nanoparticles of nickel ferrite/gold were prepared, including core/shell nanoparticles (with a nickel ferrite magnetic core and a gold plasmonic shell) and nickel ferrite nanoparticles decorated with gold nanoparticles. In order to develop applications in combined cancer therapy, the prepared nanoparticles were covered with a lipid bilayer, these systems being able to transport drugs. The heating capabilities of the nanosystems were evaluated through the fluorescence quenching of the dye rhodamine B incorporated in the lipid bilayer upon excitation with a light source. The developed multifunctional nanosystems have shown promising results for application in combined cancer therapy (chemo/phototherapy).
Magneto-sensitive liposomes can be obtained by encapsulation of magnetic nanoparticles into liposomes or by the coverage of magnetic nanoparticles with a lipid bilayer. The so-called magnetoliposomes make possible to explore the synergistic effect between chemotherapy and magnetic hyperthermia in cancer therapeutics. Both aqueous magnetoliposomes (magnetic nanoparticles entrapped in liposomes) and solid magnetoliposomes (clusters of nanoparticles covered by a lipid bilayer), containing biocompatible magnetic nanoparticles, have been developed, exhibiting a superparamagnetic behavior and diameters below 150 nm. These nanosystems were successfully tested as nanocarriers for fluorescent potential antitumor drugs. Drug-loaded magnetoliposomes have shown the ability to interact by fusion with models of biomembranes and to release the antitumor drugs in in vitro assays using human tumor cell lines. Fluorescencebased methodologies, including Förster Resonance Energy Transfer (FRET), emission quenching and fluorescence anisotropy, have been used as valuable tools for this investigation.