1H NMR Relaxometric Analysis of Paramagnetic Gd2O3:Yb Nanoparticles Functionalized with Citrate Groups

Abstract

Gd2O3 nanoparticles doped with different amount of Yb3+ ions and coated with citrate molecules were prepared by a cheap and fast co-precipitation procedure and proposed as potential “positive” contrast agents in magnetic resonance imaging. The citrate was used to improve the aqueous suspension, limiting particles precipitation. The relaxometric properties of the samples were studied in aqueous solution as a function of the magnetic field strength in order to evaluate the interaction of the paramagnetic ions exposed on the surface with the water molecules in proximity. The nanoparticles showed high relaxivity values at a high magnetic field with respect to the clinically used Gd3+-chelates and comparable to those of similar nanosytems. Special attention was also addressed to the investigation of the chemical stability of the nanoparticles in biological fluid (reconstructed human serum) and in the presence of a chelating agent.

Recent advances in development of nanomedicines for multiple sclerosis diagnosis

“…In in vitro MRI experiments, they found both PEGylated Gd 2 (CO 3 ) 3 particles and Gd 2 O 3 nanoparticles were biocompatible and displayed a high longitudinal relaxation rate. Other strategies have been applied to modify Gd 2 O 3 nanoparticles with great compatibility and multimodalities for clinical use, such as laser ablation in liquid synthesized Europium-doped gadolinium oxide (Gd 2 O 3 :Eu 3+ ) nanoparticles as dual-modal contrast agents [90][91][92], praseodymium-doped gadolinium oxide (Gd 2 O 3 :Pr 3+ ) nanospheres as bifunctional contrast agents [93], Ytterbium-doped gadolinium oxide (Gd 2 O 3 :Yb 3+ ) nanoparticles as dual MRI-CT contrast agents [94] and Gd 2 O 3 nanoparticles coated with a fluorescent carbon layer as bifunctional nanoprobes [95]. However, since in vivo studies and clinical trials of these Gd 2 O 3based nanoparticles are scarce, their clinical applicability and imaging efficiency are still in need of further investigations.…”

Smart Tools for Smart Applications: New Insights into Inorganic Magnetic Systems and Materials

“…Carniato and Gatti [10] contributed to the Special Issue with an interesting research article dealing with Gd 2 O 3 nanoparticles doped with various amounts of Yb 3+ . These mixed oxide nanoparticles were already proposed as a potential dual computed tomography (CT) and positive MRI contrast agent [11].…”