title: T1-T2Dual-modal MRI contrast agents based on superparamagnetic iron oxide nanoparticles with surface attached gadolinium complexes.
abstract: Dual-mode MRI contrast agents consisting of superparamagnetic iron oxide nanoparticle (SPION) cores and gadolinium ions associated with the ionic chitosan protecting layer were synthesized and studied. Gadolinium ions were introduced into the coating layer via direct complex formation on the nanoparticles surface, covalent attachment or electrostatically driven deposition of the preformed Gd complex. The modified SPIONs having hydrodynamic diameters ca. 100 nm form stable, well-defined dispersions in water and have excellent magnetic properties. Physiochemical properties of those new materials were characterized using e.g., FTIR spectroscopy, dynamic light scattering, X-ray fluorescence, TEM, and vibrating sample magnetometry. They behave as superparamagnetics and shorten both T1and T2proton relaxation times, thus influencing both r1and r2relaxivity values that reach 53.7 and 375.5 mM-1s-1, respectively, at 15 MHz. The obtained materials can be considered as highly effective contrast agents for low-field MRI, particularly useful at permanent magnet-based scanners.
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szpak
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Fiejdasz
authors.affiliation: Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Prendota
authors.affiliation: Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Strączek
authors.affiliation: Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
authors.forename: Czesław
authors.initials: C
authors.lastname: Kapusta
authors.affiliation: Faculty of Energy and Fuels, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Szmyd
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Nowakowska
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Szczepan
authors.initials: S
authors.lastname: Zapotoczny
keywords: Chitosan; Composite nanoparticles; Gadolinium; Magnetic resonance imaging; Relaxivity; SPION; Superparamagnetic nanoparticles