title: Water-dispersible ferrimagnetic iron oxide nanocubes with extremely high r₂ relaxivity for highly sensitive in vivo MRI of tumors.
abstract: The theoretically predicted maximum r(2) relaxivity of iron oxide nanoparticles was achieved by optimizing the overall size of ferrimagnetic iron oxide nanocubes. Uniform-sized iron oxide nanocubes with an edge length of 22 nm, encapsulated with PEG-phospholipids (WFION), exhibited high colloidal stability in aqueous media. In addition, WFIONs are biocompatible and did not affect cell viability at concentrations up to 0.75 mg Fe/ml. Owing to the enhanced colloidal stability and the high r(2) relaxivity (761 mM(-1) s(-1)), it was possible to successfully perform in vivo MR imaging of tumors by intravenous injection of 22-nm-sized WFIONs, using a clinical 3-T MR scanner.
authors.affiliation: World Class University Program of Chemical Convergence for Energy and Environment, Institute of Chemical Processes, and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Nohyun
authors.initials: N
authors.lastname: Lee
authors.forename: Yoonseok
authors.initials: Y
authors.lastname: Choi
authors.forename: Youjin
authors.initials: Y
authors.lastname: Lee
authors.forename: Mihyun
authors.initials: M
authors.lastname: Park
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.forename: Taeghwan
authors.initials: T
authors.lastname: Hyeon
mesh_terms: D045744:Cell Line, Tumor; D003287:Contrast Media; D004058:Diffusion; D005290:Ferric Compounds; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D009374:Neoplasms, Experimental / Q000473:pathology*; D014867:Water / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D014867:Water; C000499:ferric oxide