Simple Synthesis and Functionalization of Iron Nanoparticles for Magnetic Resonance Imaging

摘要

Magnetic nanoparticles (NPs) are increasingly important in many biomedical applications, such as drug delivery, hyperthermia, and magnetic resonance imaging (MRI) contrast enhancement. For MRI, iron oxide NPs are the only commercial T2 or negative contrast agents, due to their biocompatibility and ease of synthesis and research in the area is highly active.The efficacy of these contrast agents depends mainly on the surface chemistry and magnetic properties of the NPs. Materials with larger magnetization could induce more efficient transverse (T2) relaxation of protons and result in greater contrast enhancement. As iron has the highest saturation magnetization at room temperature among all elements, and is biocompatible, it is an ideal candidate for MRI contrast enhancement. Nevertheless, the development of using iron NPs for magnetic applications has been challenging and limited compared to those of its oxides, due to the difficulty in preparing stable iron NPs with simple synthesis methods and precursors.