Synthesis and Characterization of Tb³⁺-Doped Gd₂O₃ Nanocrystals: A Bifunctional Material with Combined Fluorescent Labeling and MRI Contrast Agent Properties

Abstract

Ultrasmall gadolinium oxide nanoparticles doped with terbium ions were synthesized by the polyol route and characterized as a potentially bifunctional material with both fluorescent and magnetic contrast agent properties. The structural, optical, and magnetic properties of the organic-acid-capped and PEGylated Gd 2 O 3 :Tb 3+ nanocrystals were studied by HR-TEM, XPS, EDX, IR, PL, and SQUID. The luminescent/fluorescent property of the particles is attributable to the Tb 3+ ion located on the crystal lattice of the Gd 2 O 3 host. The paramagnetic behavior of the particles is discussed. Pilot studies investigating the capability of the nanoparticles for fluorescent labeling of living cells and as a MRI contrast agent were also performed. Cells of two cell lines (THP-1 cells and fibroblasts) were incubated with the particles, and intracellular particle distribution was visualized by confocal microscopy. The MRI relaxivity of the PEGylated nanoparticles in water at low Gd concentration was assessed showing a higher T 1 relaxation rate compared to conventional Gd-DTPA chelates and comparable to that of undoped Gd 2 O 3 nanoparticles.

Hyaluronic acid-functionalized bismuth oxide nanoparticles for computed tomography imaging-guided radiotherapy of tumor

“…3-(4,5-Dimethyl-thiazol-2-yl)-5-(3-carbo xymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) was purchased from Promega (Cell Titer Aqueous One Solution Cell Proliferation Assay kit; Madison, WI, USA). The HA-Bi 2 O 3 NPs were prepared using a slightly modified procedure of the "polyol" method developed by Petoral et al 35 Specifically, 5.7 mmol BiCl 3 was dissolved in 30 mL of diethylene glycol (DEG) and constantly stirred to form a transparent viscous solution. The solution was heated in a silicon oil bath at 140°C-160°C for 1 h. Then, 7.5 mmol NaOH dissolved in 30 mL of DEG was added.…”

Structure of a hepta-nuclear termetallic oxo-alkoxide: Eu3K3TiO2(OBut)11(OMe/OH)(HOBut)

“…Large Ln-O-R angles are common for Ln-alkoxides and terminal M-O-C angles of 164-177° are found for Eu 5 O(OPr i ) 13 [33]. The tetrahedron is distorted from ideal symmetry with the apical titanium atom pointing in the direction of two of the potassium atoms, with which it shares one alkoxo bridge each.…”

“…signal enhancement and frequency up-conversion in fibers and integrated optic communication devices, lasers and fluorescent light emitters [7][8][9][10][11], nanoparticular optic and magnetic bio-markers [12][13] and heterogeneous catalysts [14]. Lanthanide ions are also important components of electroceramics as silent spacer atoms in e.g.…”

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

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The studies conducted so far have investigated the relaxometric properties, surface functionalizations, and in vivo MR images of Gd 2 O 3 nanoparticles. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] A particle-size effect on the relaxometric properties of lanthanide oxide nanoparticles has been reported. 1,17,19 However, the effects of ligands on the relaxometric properties of ultrasmall Gd 2 O 3 nanoparticles have rarely been studied.…”