Iron Oxide Nanocubes Enhance MRI

Uniformly sized iron oxide nanoparticles can be used as contrast agents for single-cell and other ultrasensitive magnetic resonance imaging applications, according to researchers in South Korea (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1016409108). The study could advance basic research in biology and lead to new methods for clinical diagnosis and therapy. Nohyun Lee and Taeghwan Hyeon of Seoul National University and coworkers used colloidal chemistry to prepare ferrimagnetic magnetite nanocubes coated with a polyethylene glycol-phospholipid matrix. The team demonstrated with a series of imaging tests and magnetization measurements that the nanoparticles outperform commercial and experimental contrast-enhancing agents for imaging and tracking cells in vitro and in vivo. Specifically, the researchers used the nanocubes to image human breast cancer cells in vitro and single rat cells in vivo. They also imaged pancreatic islets transplanted into the liver of rats and pigs by using a clinical MRI scanner.