Synthesis and characterization of radiopaque magnetic core-shell nanoparticles for X-ray imaging applications

Abstract

Radiopaque magnetic γ-Fe2O3/poly(2- methacryloyloxyethyl(2,3,5-triiodobenzoate)) core-shell nanoparticles of narrow size distribution were prepared by emulsion polymerization of the iodinated monomer 2-methacryloyloxyethyl(2,3,5-triiodobenzoate) in the presence of maghemite (γ-Fe2O3) nanoparticles of about 15 nm average diameter. The effect of the iodinated monomer concentration on the percent of the radiopaque shell coating has been elucidated. Characterization of these radiopaque core-shell particles was accomplished by methods such as FTIR, TGA, TEM, HRTEM, iodine analysis, and magnetic susceptibility measurements. The radiopacity of the dried and water dispersed core-shell nanoparticles was demonstrated by an imaging technique based on X-ray absorption usually used in hospitals. γ-Fe2O3 nanoparticles coated with a dextran shell are commonly used as contrast agents for magnetic resonance imaging (MRI). The present nanoparticles have similar core-shell structure substituting the dextran for the iodo polymer. These core-shell nanoparticles may therefore be useful as imaging contrast agents to detect various pathogenic zones and to observe different disease states in both modes: X-ray and MRI. © 2007 Wiley Periodicals, Inc.