In vitroandin vivoexperiments with iron oxide nanoparticles functionalized with DEXTRAN or polyethylene glycol for medical applications: Magnetic targeting

In this research work, DEXTRAN- and polyethyl- ene glycol (PEG)-coated iron-oxide superparamagnetic nano- particles were synthetized and their cytotoxicity and biodistribution assessed. Well-crystalline hydrophobic Fe3O4 SPIONs were formed by a thermal decomposition process with d 5 18 nm and r 5 2 nm; finally, the character of SPIONs was changed to hydrophilic by a post-synthesis pro- cedure with the functionalization of the SPIONs with PEG or DEXTRAN. The nanoparticles present high saturation mag- netization and superparamagnetic behavior at room tempera- ture, 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 Spe- cific Power Absorption SPA of 320 and 400 W/g, respectively, in an ac magnetic field with amplitude of 13 kA/m and fre- quency 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 lg/mL. In vivo studies were conducted using BALB/c mice inoculating the SPIONs intrave- nously 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 exter- nal magnetic field. V C