title: Iron hydroxide nanoparticles coated with poly(ethylene glycol)-poly(aspartic acid) block copolymer as novel magnetic resonance contrast agents for in vivo cancer imaging.
abstract: PEG-coated beta-FeOOH nanoparticles were prepared through electrostatic complex formation of iron oxide nanoparticles with poly(ethylene glycol)-poly(aspartic acid) block copolymer [PEG-P(Asp)] in distilled water. By dynamic light scattering (DLS) measurement, the nanopaticle size was determined to be 70 nm with narrow distribution. The FT-IR and zeta potential experimental results proved that PEG-PAsp molecules bound to the surface of the iron oxide nanoparticles via the coordination between the carboxylic acid residues in the PAsp segment of the block copolymer and the surface Fe of the beta-FeOOH nanoparticles. The PEG-coated nanoparticles revealed excellent solubility and stability in aqueous solution as well as in physiological saline. In vivo MRI experiments on tumor-bearing mice demonstrated that the PEG-coated nanoparticles prepared by the current approach achieved an appreciable accumulation into solid tumor, suggesting their potential utility as tumor-selective MRI contrast agents.
authors.affiliation: Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Kumagai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imai
authors.forename: Teisaku
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: Masaki
authors.initials: M
authors.lastname: Sekino
authors.forename: Shoogo
authors.initials: S
authors.lastname: Ueno
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Hanaoka
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nagano
authors.forename: Eiji
authors.initials: E
authors.lastname: Kaneko
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shimokado
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kataoka
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003110:Colonic Neoplasms / Q000473:pathology; D003287:Contrast Media / Q000737:chemistry; D005260:Female; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods; D051379:Mice; D008815:Mice, Inbred Strains; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000175:diagnosis*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D020099:Coated Materials, Biocompatible; D003287:Contrast Media; D006878:Hydroxides; D011108:Polymers; D001224:Aspartic Acid; D011092:Polyethylene Glycols; C031356:hydroxide ion; D007501:Iron