Sweet Nanoparticle Imaging

University of Oxford researchers have devised sugar-coated nanoparticles that could improve the diagnosis of disease-associated lesions in the brain (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0806787106). Benjamin G. Davis, Nicola R. Sibson, Daniel C. Anthony, and coworkers began by attaching glycan ligands to amine-functionalized, dextran-coated iron oxide nanoparticles. The best ligand they tried is sialyl Lewis^X, a tetrasaccharide that targets selectins, which are carbohydrate-binding proteins involved in inflammation. The team modified the ligand with an S-cyanomethyl linker that serves as a protecting group until the ligand is added to the nanoparticle. The team used the resulting glyconanoparticles as contrast agents in magnetic resonance imaging studies of rats afflicted with conditions similar to multiple sclerosis or stroke. The glyconanoparticles revealed lesions in these disease models at an earlier stage than did other MRI contrast agents, a result that the researchers suggest could lead to methods for earlier diagnoses.