Iron Oxide Nanoparticles Are Less Toxic to Endothelial Cells When Coated With Dextran and Polyethylene Glycol

Iron oxide nanoparticles are of particular interest for drug delivery applications, since they can be targeted to a specific location using a magnetic field. We are interested in delivering drugs to atherosclerotic plaques via these nanoparticles. However, prior to using nanoparticles in vivo, they must be shown as relatively non-toxic to cells. We and others have shown that bare iron oxide nanoparticles are readily taken up by cells, where they catalyze production of highly toxic reactive oxygen species [1]. This oxidative stress disrupts the cell cytoskeleton, alters cell mechanics, and may change other critical cell functions. Iron oxide nanoparticles for in vivo biomedical applications are often coated with a polysaccharide (eg. dextran) or a polymer (eg. polyethylene glycol, PEG). Both the size and the surface coating of the nanoparticle play an important role in cell toxicity.