title: Ferromagnetic FePt-nanoparticles/polycation hybrid capsules designed for a magnetically guided drug delivery system.
abstract: The present Article describes the synthesis of ferromagnetic capsules approximately 330 nm in diameter with a nanometer-thick shell to apply to magnetic carriers in a magnetically guided drug delivery system. The magnetic shell of 5 nm in thickness is a nanohybrid, composed of ordered alloy FePt nanoparticles of approximately 3-4 nm in size and a polymer layer of a cationic polyelectrolyte, poly(diaryldimethylammonium chloride) (PDDA). The magnetic capsules have an excellent capacity for carrying medical drugs and genes. Surface-modified silica particles with PDDA were used as a template for the capsules. FePt nanoparticles were deposited on the PDDA-modified silica particles through a polyol method followed by dissolving the silica particles with a NaOH solution, resulting in the formation of the magnetic capsules as the final product. A three-dimensional hollow structure is maintained by the nanohybrid shell. The FePt-nanoparticles/PDDA nanohybrid shell also exhibits a ferromagnetic feature at room temperature because the FePt nanoparticles of an ordered-alloy phase are formed with the aid of PDDA despite the small size (3-4 nm).
authors.affiliation: Department of Innovative and Engineered Materials, Tokyo Institute of Technology , J2-40, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
authors.forename: Teruaki
authors.initials: T
authors.lastname: Fuchigami
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawamura
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kitamoto
authors.forename: Masaru
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Namiki
mesh_terms: D002214:Capsules / Q000737:chemistry; D016503:Drug Delivery Systems; D007501:Iron / Q000737:chemistry*; D060526:Magnetic Fields; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D000071228:Polyelectrolytes; D013499:Surface Properties
chemical_list: D002214:Capsules; D007501:Iron; D010984:Platinum; D011073:Polyamines; D000071228:Polyelectrolytes