A Facile Synthesis, In vitro and In vivo MR Studies of d-Glucuronic Acid-Coated Ultrasmall Ln₂O₃ (Ln = Eu, Gd, Dy, Ho, and Er) Nanoparticles as a New Potential MRI Contrast Agent

Abstract

A facile one-pot synthesis of d-glucuronic acid-coated ultrasmall Ln(2)O(3) (Ln = Eu, Gd, Dy, Ho, and Er) nanoparticles is presented. Their water proton relaxivities were studied to address their possibility as a new potential MRI contrast agent. We focused on the d-glucuronic acid-coated ultrasmall Dy(2)O(3) nanoparticle because it showed the highest r(2) relaxivity among studied nanoparticles. Its performance as a T(2) MRI contrast agent was for the first time proved in vivo through its 3 T T(2) MR images of a mouse, showing that it can be further exploited for the rational design of a new T(2) MRI contrast agent at high MR fields.

Silica-Coated Europium-Doped Gadolinium Oxide Nanorods for Dual-Modal Imaging of Cancer Cells

“…Therefore, it results in the formation of Eu:Gd (OH) 3 nanoparticles rather than the formation of Eu:Gd 2 O 3 nanoparticles. 25 The formation of`rodlike' structures is due to the structure of Eu:Gd (OH) 3 nanoparticles. They have a hexagonal crystal structure which favors the growth of crystals in one direction.…”

Ligand-size and ligand-chain hydrophilicity effects on the relaxometric properties of ultrasmall Gd2O3 nanoparticles

“…In contrast, the T 2 relaxation is mainly induced by the interaction of the water proton spin with the fluctuating local magnetic field generated by the nanoparticle magnetic moment of M NP (≈  all i S i in the case of Gd 2 O 3 nanoparticles). 19,[21][22][23] Because all factors except for the ligand are held constant for all samples, including the particle diameter, solution, pH, temperature, and applied MR field, and because the magnetic dipole interaction between two dipoles decreases inverse-cubically with their separation, r 1 and r 2 may be roughly formulated as follows.…”

“…In contrast, the transverse (or T 2 ) water proton spin relaxation is mainly induced by the interaction of the water proton spin with the fluctuating local magnetic field generated by the total nanoparticle magnetic moment of the contrast agent (that is, the magnetic moment arising from both the spin and orbital motions of the electrons of the metals contributes to the T 2 relaxation). 19,[21][22][23] Therefore, ultrasmall Gd 2 O 3 nanoparticles can contribute to both the T 1 and T 2 relaxations because Gd 3+ has a pure spin of 7/2 arising from its 7 unpaired 4f-electrons, which is the largest pure spin in the periodic table. Based on this fact and using a simple magnetic dipole interaction model, two types of ligand effects are addressed in this study.…”

Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches

“…A way to solve this problem relies in the synthesis of Gdbased paramagnetic NPs [68] , such as Ln 2 O 3 , GdF 3 , and GdPO 4 [26,69,70] , which yield high magnetic moments because of the abundance of paramagnetic ions on their surfaces.…”