Synthesis of Pseudopolyrotaxanes-Coated Superparamagnetic Iron Oxide Nanoparticles as MRI Contrast Agent

Superparamagnetic iron oxide nanoparticles (SPIONs) have been recognized as a powerful tool for various biomedical applications such as targeting drug delivery [1], magneticresonance imaging (MRI), hyperthermia, cell/protein separation, and tissue repair. In order to increase theperformance and safety of the SPIONs, for biomedical applications, several new coatings have been developed. Polyrotaxanes (PRs) are high-functionality supramoleculesconsisting of several rings and one or more axes, in which the dissociation of ring from axis is hindered by bulky groups, theso-called stoppers, at both ends of the axis [2]. It is notable that PRs without stoppers are called pseudo polyrotaxanes (PPRs). Herein PPRs consisting of polyethylene glycol axesand cyclodextrin rings have been used as new shells for SPIONs in order to create the new bicompatibleSPIONs@PRs hybrid nanomaterials with enhanced functionality. As a result due to their biocompatible and highly functional shell, the synthesized SPIONs@PRs hybridnanomaterials can be used for a wide variety of biomedical applications such as imaging and targeted drug delivery systems.