title: Highly water-dispersible PEG surface modified ultra small superparamagnetic iron oxide nanoparticles useful for target-specific biomedical applications.
abstract: For the application of superparamagnetic iron oxide nanoparticles in biomedical fields for target-specific purposes, they should be ultra small in diameter. We developed a simple one-step synthesis of surface modified ultra small superparamagnetic iron oxide nanoparticles (USPIONs) with an average particle diameter of 1.7 nm in a polar organic solvent. Polyethylene glycol diacid (PEG) surface modified USPIONs synthesized in triethylene glycol were nearly monodisperse in diameter and highly water-dispersible. The PEG surface modified USPIONs were tested for use as magnetic resonance (MR) contrast agents. They had a low r(2)/r(1) relaxivity ratio of 3.4 (r(1) = 4.46 and r(2) = 15.01 mM(-1) s(-1)) and showed clear dose-dependent T(1) and T(2) map images, indicating that they will be useful as both target-specific T(1) and T(2) MR contrast agents due to their ultra small size.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Kyungpook National University, Taegu 702-701, Korea.
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Park
authors.forename: Patel
authors.initials: P
authors.lastname: Daksha
authors.forename: Gang Ho
authors.initials: GH
authors.lastname: Lee
authors.forename: Seungtae
authors.initials: S
authors.lastname: Woo
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Chang