Magnetic Iron Oxide Nanoparticles for Biomedical Applications.

Owing to the quantum confinement at the nanoscale, magnetic iron oxide nanoparticles (MIONs) consisting of magnetite and maghemite nanocrystals have unique physical properties, enabling a wide range of biomedical applications by utilizing mechanical, magnetic, chemical, and thermal effects of MIONs respectively. For example, MIONs can serve as a contrast agent for magnetic resonance imaging (MRI), convert electromagnetic energy into thermal energy for hyperthermia therapy, and carry drug/gene for targeted in vivo delivery. In this review, we discuss the recent development of MION based engineering approaches and their biomedical applications, including sensitive protein quantification, magnetic nanoparticle heating, in vivo molecular imaging, and drug delivery. The opportunities and challenges in further exploring the biomedical applications of MIONs are also briefly discussed.