title: Highly monodisperse low-magnetization magnetite nanocubes as simultaneous T(1)-T(2) MRI contrast agents.
abstract: We report the first study of highly monodisperse and crystalline iron oxide nanocubes with sub-nm controlled size distribution (9.7 ± 0.5 nm in size) that achieve simultaneous contrast enhancement in both T1- and T2-weighted magnetic resonance imaging (MRI). Here, we confirmed the magnetite structure of iron oxide nanocubes by X-ray diffraction (XRD), selected area electron diffraction (SAED) pattern, optical absorption and Fourier transformed infrared (FT-IR) spectra. These magnetite nanocubes exhibit superparamagnetic and paramagnetic behavior simultaneously by virtue of their finely controlled shape and size. The magnetic measurements reveal that the magnetic moment values are favorably much lower because of the small size and cubic shape of the nanoparticles, which results in an enhanced spin canting effect. As a proof-of-concept demonstration, we showed their potential as dual contrast agents for both T1- and T2-weighted MRI via phantom studies, in vivo imaging and relaxivity measurements. Therefore, these low-magnetization magnetite nanocubes, while being non-toxic and bio-compatible, hold great promise as excellent dual-mode T1 and T2 contrast agents for MRI.
authors.affiliation: UNAM-Institute of Materials Science and Nanotechnology, National Magnetic Resonance Research Center (UMRAM), Department of Electrical and Electronics Engineering, Department of Physics, Department of Molecular Biology and Genetics, Bilkent University, Ankara, 06800, Turkey.
authors.forename: V K
authors.initials: VK
authors.lastname: Sharma
authors.forename: A
authors.initials: A
authors.lastname: Alipour
authors.forename: Z
authors.initials: Z
authors.lastname: Soran-Erdem
authors.forename: Z G
authors.initials: ZG
authors.lastname: Aykut
authors.forename: H V
authors.initials: HV
authors.lastname: Demir
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000138:chemical synthesis / Q000633:toxicity*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D007089:Image Enhancement / Q000379:methods; D007668:Kidney / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000633:toxicity* / Q000648:ultrastructure; D008422:Materials Testing; D051379:Mice; D010316:Particle Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles