HER2/neu Antibody Conjugated Poly(amino acid)-Coated Iron Oxide Nanoparticles for Breast Cancer MR Imaging

Abstract

Superparamagnetic iron oxide nanoparticles are widely used as nanoprobes for magnetic resonance imaging (MRI). Water-soluble iron oxide nanoparticles were synthesized by coating iron oxide nanoparticles with a hydrophilic, biocompatible, biodegradable poly(amino acid) derivative, poly(2-hydroxyethyl aspartamide) graft copolymer for negative contrast enhancement on T2 weighted MRI. HER2/neu antibodies were conjugated on the surface of poly(amino acid) coated iron oxide nanoparticles for the detection of breast cancer. The antibody-grafted iron oxide nanoparticles (PAION-Ab) were about 31.1 nm in diameter. The T2 relaxivity of PAION-Ab was 246 L·mmol-1 · sec-1 greater than that of the commercial product such as Feridex. PAION-Ab showed low cytotoxicity even at relatively high concentrations. Furthermore, Prussian blue staining and in vitro MRI study with SKBR-3, breast cancer cells overexpressing HER2/neu receptors indicated that PAION-Ab exhibited excellent cancer cell detection ability and enhanced signal intensities in the T2-weighted image.