Development of PEGylated organic-inorganic hybrids as potential contrast agents for medical imaging

PMSE 178

Jean-François Lutz, lutz@iap.fhg.de and Erik Ortel. Nanotechnology for Life Science, Fraunhofer Institute for Applied Polymer Research, Geiselbergstrasse 69, Potsdam, 14476, Germany
A simple ionic self-assembly process was investigated for constructing tailor-made biocompatible contrast agents for magnetic resonance imaging. In this approach, cationic materials (i.e. cationic surfaces of superparamagnetic iron oxide nanoparticles or gadolinium cations) were complexed with well-defined polyanions prepared using atom transfer radical polymerization (ATRP). The synthesized polymers (block and random copolymers) contained anionic sites (i.e. acrylic acid or methacrylic acid units) and biocompatible poly- or oligo-(ethylene glycol) segments. These well-defined polymers allowed preparation of monodisperse ultrasmall superparamagnetic iron oxide nanoparticles and defined polymer-gadolinium aggregates. Examples of in vivo applications of these novel contrast agents are discussed herein.