title: Properties evaluation of a new MRI contrast agent based on Gd-loaded nanoparticles.
abstract: Nanosized materials of gadolinium oxide can provide high-contrast enhancement in magnetic resonance imaging (MRI). The aim of this research was to characterize a novel emulsion composed of a silicon-based nanocomposite polymer (NCP) and gadolinium (III) oxide (Gd₂O₃) nanoparticles. The size and morphological structure of this nanoparticle are determined by particle size analysis device (zeta sizer) and transmission electronic microscope. We determined composition of Gd₂O₃ nanoparticles with energy dispersive X-ray analysis (EDXA) and magnetic resonance signal by T₁-weighted MRI. Cytotoxicity of Gd₂O₃ nanoparticles in SK-MEL-3 cancer cells was evaluated. Zeta sizer showed Gd₂O₃ nanoparticles to be 75 nm in size. EDXA indicated the two main chemical components of gadolinium-nanocomposite polymer emulsion: gadolinium and silicon and MRI also showed a significantly higher incremental relaxivity for Gd₂O₃ nanoparticles compared to Magnevist (conventional contrast agent). In such concentrations, the slope of R₁ relaxivity (1/T₁) vs. concentration curve of Magnevist and Gd₂O₃ were 4.33, 7.98 s⁻¹ mM⁻¹. The slope of R₂ relaxivity (1/T₂) vs. concentration curve of Magnevist and Gd₂O₃ were 5.06, 13.75 s⁻¹ mM⁻¹. No appreciable toxicity was observed with Gd₂O₃ nanoparticles. Gadolinium-nanocomposite polymer emulsion is well characterized and has potential as a useful contrast agent for magnetic resonance molecular imaging.
authors.affiliation: Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Riyahi-Alam
authors.forename: Zhaleh
authors.initials: Z
authors.lastname: Behrouzkia
authors.forename: Alexander
authors.initials: A
authors.lastname: Seifalian
authors.forename: Soheila
authors.initials: S
authors.lastname: Haghgoo Jahromi
mesh_terms: D045744:Cell Line, Tumor; D003287:Contrast Media / Q000737:chemistry / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical; D005682:Gadolinium / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D053761:Nanocomposites; D053758:Nanoparticles
chemical_list: D003287:Contrast Media; C030581:gadolinium oxide; D005682:Gadolinium