Poly(N-isopropyl acrylamide) coated magnetite nanoparticles as contrast agents for magnetic resonance imaging

Abstract

Thermosensitive poly(N-isopropyl acrylamide) (PNIPAM) has been coated on Fe3O4 core to prepare Fe3O4-PNIPAM core–shell nanostructures. The PNIPAM coating has the ability to swell and shrink due to changes in temperature. Core–shell nanostructured samples with different hydrodynamic sizes were prepared. Zeta potential measurements showed that these samples are highly stable in aqueous environment. These core–shell structures were shown to be better contrast agents than conventional Gd chelates for magnetic resonance imaging (MRI). Thus this core–shell Fe3O4-PNIPAM system can be used for multimodal theranostics as a drug carrier, hyperthermia agent and for MRI.