Manipulating the surface coating of ultra-small Gd2O3 nanoparticles for improved T1-weighted MR imaging

Glycine–Nitrate Process for the Elaboration of Eu3+‐Doped Gd2O3 Bimodal Nanoparticles for Biomedical Applications

“…With regard to the longitudinal relaxivity, there is no significant difference with the data reported for analogous Gd 2 O 3 materials ( Table 2). As demonstrated in various reports, [71][72][73][74][75][76][77][78][79] the r 1 and r 2 relaxivities of the nanoparticles decrease as the particle size increases; this explains our low r 1 measurements. The r 1 relaxivity can have contributions from the inner-sphere and outer-sphere mechanisms.…”

“…The water 1 H relaxivity values (r 1 and r 2 ) and the r 2 /r 1 values measured at 20 MHz and at 25 and 37°C for clear dispersions of the Gd 2 O 3 and Eu:Gd 2 O 3 nanoparticles in water are listed in Table 2 and compared with literature data. [70][71][72][73][74][75][76][77][78][79] The proton relaxivities (r i ) were obtained from the observed linear dependence of the relaxation rates R i (R i = 1/T i , i = 1, 2) on the concentration of the Gd 3+ ions in the samples, and at least four independent measurements at concentrations between 0 and 1 mm were used ( Table 2, see also Figures S4 and S5). The r 1 values are quite low for all of the samples studied, and the r 2 values are slightly larger.…”

Fabrication and evaluation of tumor-targeted positive MRI contrast agent based on ultrasmall MnO nanoparticles

“…Especially, the application of inorganic nanoparticles as contrast agent of MRI has gained considerable attention due to relatively high stability and good MRI function [14]. For example, gadolinium compound-based crystalline nanoparticles, such as the Gd-containing nanoparticles of Gd 2 O 3 , GdF 3 and NaGdF 4 , provide a rigid crystal environment that is effectively prevent nanoparticles from releasing free gadolinium ions, and so that they have been mostly investigated as a new generation of positive contrast agents [15][16][17]. As well-known, manganese ion has five unpaired electron, and the spin of them results in an efficient shortening of longitudinal relaxation time of proton in water together with the enhancement of magnetic resonance signal intensity [18,19].…”

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

“…Supporting this explanation, enhanced relaxometric properties of ultrasmall Gd 2 O 3 nanoparticles have been observed after replacing a hydrophobic ligand with a hydrophilic ligand. 39 Therefore, both the ligand-size and ligand-chain hydrophilicity effects are important for determining the relaxometric properties of ultrasmall Gd 2 O 3 nanoparticles. This result suggests that a large ligand with hydrophilic chains may be preferable for surface-coating when both a high water solubility and good relaxometric properties are desired.…”