title: Facile non-hydrothermal synthesis of oligosaccharides coated sub-5 nm magnetic iron oxide nanoparticles with dual MRI contrast enhancement effect.
abstract: Ultrafine sub-5 nm magnetic iron oxide nanoparticles coated with oligosaccharides (SIO) with dual T1-T2weighted contrast enhancing effect and fast clearance has been developed as magnetic resonance imaging (MRI) contrast agent. Excellent water solubility, biocompatibility and high stability of such sub-5 nm SIO nanoparticles were achieved by using the "in-situpolymerization" coating method, which enables glucose forming oligosaccharides directly on the surface of hydrophobic iron oxide nanocrystals. Reported ultrafine SIO nanoparticles exhibit a longitudinal relaxivity (r1) of 4.1 mM-1s-1and a r1/r2ratio of 0.25 at 3 T (clinical field strength), rendering improved T1or "brighter" contrast enhancement in T1-weighted MRI in addition to typical T2or "darkening" contrast of conventional iron oxide nanoparticles. Such dual contrast effect can be demonstrated in liver imaging with T2"darkening" contrast in the liver parenchyma but T1"bright" contrast in the hepatic vasculature. More importantly, this new class of ultrafine sub-5 nm iron oxide nanoparticles showed much faster body clearance than those with larger sizes, promising better safety for clinical applications.
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
authors.affiliation: MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia 30322, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Yuancheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Surgery, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Lily
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao