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.

Gadolinium Labeled Glycosylated Nanomagnetic Particles as Metabolic Contrast Agents in Molecular Magnetic Resonance Imaging

“…The excess of Gd ions and agglomerated nanoparticle in the solution was eliminated by 1000MW membrane (Dialysis tubing, benzoylated, Sigma, USA) for 24h and of 12000MW membrane (Dialysis tubing cellulose membrane, Sigma, USA) for 24h across idolized water. [7,8,9] GD-DEG-DG: 5mg ml -1 0f DEG-Gd2O3 was washed sequentially with 10 ml each of DI water, THF-DI water and finally with anhydrous THF for several repeated washes to eliminate any remaning traces of water. carbonyldiimidazole (CDI) was then added into the suspension at a concentration of 50 mg ml -1 and reacted at 700rpm mixing in a shaker for 2h at room temperature.…”

Synthesis route and three different core-shell impacts on magnetic characterization of gadolinium oxide-based nanoparticles as new contrast agents for molecular magnetic resonance imaging

“…After cooling, the nanocrystals formed were separated and purified from agglomerations or large-size particles by centrifuge filtration for 30 min at 40°C and 2,000 rpm (filters: polyethersulfone, 0.2 μm, Vivascience Sartorius, Hannover, Germany). Free Gd 3+ ions and excess DEG in the solution were eliminated by 1,000 MW membrane (dialysis tubing, benzoylated, Sigma-Aldrich, USA) for 24 h and by 12,000 MW membrane (dialysis tubing cellulose membrane, Sigma-Aldrich, USA) for 24 h across deionized water, which these sections were not included in our previous study [13]. …”

“…As a new surface covering material, this group in a previous study reported some of the primary magnetic properties of diethyleneglycol (DEG) in combination with Gd oxide-based nanoparticles [10]. However, still further researches on the matters of the synthesis procedure, effective size, and agglomeration of gadolinium nanoparticles coated with DEG materials are needed to be done [11-13]. On the other hand, polyethylene glycol (PEG), due to its considerable physicochemical properties, has an especial interest as covering of nanoparticle surfaces [13-17].…”

“…However, still further researches on the matters of the synthesis procedure, effective size, and agglomeration of gadolinium nanoparticles coated with DEG materials are needed to be done [11-13]. On the other hand, polyethylene glycol (PEG), due to its considerable physicochemical properties, has an especial interest as covering of nanoparticle surfaces [13-17]. Also, it should be noted that PEG has different molecular weights from 350 to 30,000 (and more) Da that could be used alone or in conjunction with other substances such as polylactide-polyethylene glycol and polylactide-co-glycolide [18-20].…”

Properties Evaluation of Gd2O3-DEG as New Contrast Agent Nanomagnetic Particles Comparing to Gd-DTPA in MRI

“…But, since Gd +3 ions have an unpaired electrons and is highly toxic, it must be coated by some suitable biocompatible chelators such as Diethylenetriaminpentaasetic acid (DTPA) [2]. Magnetic resonance imaging (MRI) is a noninvasive imaging technique capable of obtaining high-resolution anatomical images of the body.…”