Gadolinium Complexes as MRI Contrast Agents for Diagnosis

Silica Microparticles as a Solid Support for Gadolinium Phosphonate Magnetic Resonance Imaging Contrast Agents

“…M agnetic resonance imaging (MRI) is a noninvasive diagnostic technique that provides high-resolution, three-dimensional images of anatomic soft tissue. 1,2 Gd(III) complexes are widely used to increase the sensitivity of the technique, allowing images of early stages of disease to be collected. 3−6 The large number of unpaired electrons in the Gd(III) ion leads to increased proton relaxivities, with most commercial Gd(III) complexes producing values of ∼3.0 mM −1 s −1 at 37 °C and 60 MHz.…”

“…Finally, a comparison of the per-particle relaxivities measured in this study to a variety of types of materials and complexes found in the literature (Figure 2) shows that while the per-Gd relaxivities are similar, the larger particle diameter and surface area of APMS allow more Gd to be immobilized, producing higher per-particle relaxivities. 3.0 3.3 Gd-DTPA 2 3.5 3.9 In conclusion, we have developed a new class of biologically suitable MRI contrast agents that capitalize on the strong binding affinity of the NDP 2 ligand and the large internal surface area (exceeding 600 m 2 /g) of mesoporous silica. The per-Gd relaxivities were significantly higher than those of commercially available contrast agents, and the per-particle relaxivities were among the highest values measured in the literature.…”

“…Magnetic resonance imaging (MRI) is a noninvasive diagnostic technique that provides high-resolution, three-dimensional images of anatomic soft tissue. , Gd(III) complexes are widely used to increase the sensitivity of the technique, allowing images of early stages of disease to be collected. − The large number of unpaired electrons in the Gd(III) ion leads to increased proton relaxivities, with most commercial Gd(III) complexes producing values of ∼3.0 mM –1 s –1 at 37 °C and 60 MHz. Interest in improved resolution and diagnosis , has motivated research into new ligands and hybrid materials as components in new contrast agents.…”

Synthesis, Structure, Antioxidant, and Antiviral Studies on N2H5[Ln(edta)(H2O)3].5H2O (Ln = Pr, Nd, and Sm)

“…Rare earth metal-edta chelates were found to possess effective biological activities and interesting structures. [1][2][3][4] Despite several sodium, potassium, and ammonium complexes of lanthanides with amino acids have been investigated, [5][6][7][8][9] the structural studies on hydrazinium complexes are scarce in the literature. Hydrazinium cation, N 2 H 5 + is one of a few positively charged ligands that can play a duel role to satisfy both the primary and secondary valencies of the metal ions.…”