Two hybrid materials based on mesoporous silicas SBA-15 and MCM-41 functionalized with stable and electrically neutral Gd(iii) macrocyclic complexes were prepared, and their (1)H NMR relaxometric properties investigated as a function of temperature and magnetic field strength.

High-density lipoprotein (HDL) nanoparticles doped with gadolinium lipids can be used as magnetic resonance imaging diagnostic agents for atherosclerosis. In this study, HDL nanoparticles with different molar fractions of gadolinium lipids (0 < xGd-lipids < 0.33) were prepared, and the MR relaxivity values (r1 and r2) for all compositions were measured. Both r1 and r2 parameters reached a maxim...

Gastrin-releasing peptide receptor (GRPR) is differentially expressed on the surfaces of various diseased cells, including prostate and lung cancer. However, monitoring temporal and spatial expression of GRPR in vivo by clinical MRI is severely hampered by the lack of contrast agents with high relaxivity, targeting capability and tumor penetration. Here, we report the development of a GRPR-targ...

Introduction The extracellular pH (pHe) of cancers is acidic and inhibiting this acidity will inhibit metastases. Methods to image pHe in tumors based on relaxivity of a pH-dependent contrast reagent (CR), Gd-DOTA-4AmP were developed. We investigated the single injection of a mixture of DyDOTP with GdDOTA-4AmP. The ΔT1, and ΔT2* induced by the Gd-CR exhibited similar pH-dependence, while the pH...

A series of gadolinium complexes were synthesised in order to test the design of dual-modal probes that display a change in fluorescence or relaxivity response upon binding of zinc. A dansyl-DO3ATA gadolinium complex [GdL1] displayed an increase and a slight blue-shift in fluorescence in the presence of zinc; however, a decrease in relaxation rate was observed. Consequently, the ability of the ...

INTRODUCTION: The desire to perform DCE-MRI studies at ever increasing magnetic fields comes from the promise of increased spatial and temporal resolution. However, to effectively use DCE-MRI at high fields, the increasing influence of T2* on the typically T1-weighted acquisition must be understood to avoid misinterpretation of results. While R1 relaxivity has been shown to slightly decrease [6...

A bis-polyazamacrocycle, 10'-bis(acetamido)ethane-bis[1,4,7-tri(carboxymethane)-1,4,7,10-tetraazacyclododecane] (DO3A-AME-DO3A) was synthesized for application in magnetic resonance imaging. The efficacy of DO3A-AME-DO3A as non ionic magnetic contrast agent was tested by performing relaxometric studies on its gadolinium complex. The longitudinal relaxivity, r(1) and transverse relaxivity, r(2) ...

The multivalent character of dendrimers has positioned these well-defined, highly branched macromolecules at the forefront in the development of new contrast agents for biomedical magnetic resonance imaging (MRI). By modifying the periphery of the dendrimer with gadolinium(III) chelates, the relaxivity of the resulting MRI contrast agent is increased considerably, compared to low molecular weig...

Background Diffuse myocardial fibrosis is present in several cardiomyopathies. Contrast enhanced cardiac MR with T1 mapping enables quantification of diffuse fibrosis. T1 mapping is technically demanding since technical, physiological, and biochemical factors can interfere with T1 measurements. Contrast material dose, relaxivity, biodistribution, clearance, interaction with plasma proteins, and...

A simple one-step method for preparing biocompatible nanoparticles of gadolinium ferrocyanide coordination polymer KGd(H2O)2[Fe(CN)6]·H2O is reported. The crystal structure of this coordination polymer is determined by X-ray powder diffraction using the bulk materials. The stability, cytotoxicity, cellular uptake, and MR phantom and cellular imaging studies suggest that this coordination-polyme...