title: Tracking of magnetite labeled nanoparticles in the rat brain using MRI.
abstract: This study was performed to explore the feasibility of tracing nanoparticles for drug transport in the healthy rat brain with a clinical MRI scanner. Phantom studies were performed to assess the R1 ( =  1/T1) relaxivity of different magnetically labeled nanoparticle (MLNP) formulations that were based on biodegradable human serum albumin and that were labeled with magnetite of different size. In vivo MRI measurements in 26 rats were done at 3T to study the effect and dynamics of MLNP uptake in the rat brain and body. In the brain, MLNPs induced T1 changes were quantitatively assessed by T1 relaxation time mapping in vivo and compared to post-mortem results from fluorescence imaging. Following intravenous injection of MLNPs, a visible MLNP uptake was seen in the liver and spleen while no visual effect was seen in the brain. However a histogram analysis of T1 changes in the brain demonstrated global and diffuse presence of MLNPs. The magnitude of these T1 changes scaled with post-mortem fluorescence intensity. This study demonstrates the feasibility of tracking even small amounts of magnetite labeled NPs with a sensitive histogram technique in the brain of a living rodent.
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Naira P
authors.initials: NP
authors.lastname: Martínez Vera
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schmidt
authors.affiliation: Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Muenster, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Langer
authors.affiliation: Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Muenster, Germany.
authors.forename: Iavor
authors.initials: I
authors.lastname: Zlatev
authors.affiliation: JSW-Live Sciences GmbH, Grambach, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Wronski
authors.affiliation: JSW-Live Sciences GmbH, Grambach, Austria.
authors.forename: Ewald
authors.initials: E
authors.lastname: Auer
authors.affiliation: JSW-Live Sciences GmbH, Grambach, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Havas
authors.affiliation: JSW-Live Sciences GmbH, Grambach, Austria.
authors.forename: Manfred
authors.initials: M
authors.lastname: Windisch
authors.affiliation: Department of Cell Biology & Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany.
authors.forename: Hagen
authors.initials: H
authors.lastname: von Briesen
authors.affiliation: Department of Cell Biology & Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wagner
authors.affiliation: Department of Cell Biology & Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Stab
authors.affiliation: Physics Department, Schottenstein Center for the Research and Technology of the Cellome, Bar Ilan University, Ramat Gan, Israel.
authors.forename: Motti
authors.initials: M
authors.lastname: Deutsch
authors.affiliation: Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Pietrzik
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Fazekas
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Ropele
mesh_terms: D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000737:chemistry; D019047:Phantoms, Imaging; D051381:Rats; D012709:Serum Albumin / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D058185:Magnetite Nanoparticles; D012709:Serum Albumin