Microbubbles with surface coated by superparamagnetic iron oxide nanoparticles

Microbubbles (MBs) with the ability of enhancing ultrasound image contrast and delivering drugs are widely used in medical applications. By combining microbubbles and superparamagnetic iron oxide (SPIO) nanoparticles, dual-modality contrast agent for both ultrasound and magnetic resonance (MR) imaging can be obtained. In this study, we synthesized microbubbles with a novel structure, which included a nitrogen gas core, a polymer shell, and SPIO nanoparticles on the shell surfaces. In vitro experiments showed that microbubbles with such structure provided both higher ultrasound and MR enhancement than blank microbubbles without SPIO nanoparticles and previously designed SPIO-embedded microbubbles. Furthermore because SPIO-coated microbubbles have abundant amino groups on the surface, such microbubbles have potentiality for targeted imaging after specific targeted ligands or antibodies are linked. (C) 2011 Elsevier B.V. All rights reserved.