title: Amalgamation of complex iron(III) ions and iron nanoclusters with MWCNTs as a route to potential T2 MRI contrast agents.
abstract: Iron-filled multiwall carbon nanotubes (Fe@MWCNTs) were functionalized toward a variety of potential magnetic resonance imaging contrast agents. Oxidized Fe@MWNCTs were covered with PEG5000 via direct esterification or using acyl chloride derivatives. Alternatively, the latter were functionalized with an aminophenol ligand (Fe@O-MWCNT-L). Moreover, pristine Fe@MWCNTs were functionalized with N-phenylaziridine groups (Fe@f-MWCNT) via [2+1] cycloaddition of nitrene. All of these chemically modified nanotubes served as a vehicle for anchoring Fe(3+) ions. The new hybrids--Fe(III)/Fe@(f-/O-)MWCNTs--containing 6%-14% of the "tethered" Fe(3+) ions were studied in terms of the acceleration of relaxation of water protons in nuclear magnetic resonance. The highest transverse relaxivity r2=63.9±0.9 mL mg(-1) s(-1) was recorded for Fe(III)/Fe@O-MWCNT-L, while for Fe(III)/Fe@f-MWCNT, with r2=57.9±2.9 mL mg(-1) s(-1), the highest impact of the anchored Fe(III) ions was observed. The T1/T2 ratio of 30-100 found for all of the nanotube hybrids presented in this work is a very important factor for their potential application as T2 contrast agents. Increased stability of the hybrids was confirmed by ultraviolet-visible spectrophotometry.
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Nikodem
authors.initials: N
authors.lastname: Kuźnik
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Mateusz M
authors.initials: MM
authors.lastname: Tomczyk
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Marzena
authors.initials: M
authors.lastname: Wyskocka
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Przypis
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Artur P
authors.initials: AP
authors.lastname: Herman
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Rafał
authors.initials: R
authors.lastname: Jędrysiak
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK.
authors.forename: Krzysztof K
authors.initials: KK
authors.lastname: Koziol
authors.affiliation: Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Boncel
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles; D037742:Nanotubes, Carbon
keywords: Fe3+; MRI contrast agent; multiwall carbon nanotubes; transverse relaxation time T2