Background A T1 nanoparticle contrast agent showing high r1 relaxivity is desired to provide more sensitive molecular/ cellular imaging with reduced Gd dose, and may have more clinical utility than T2* (e.g., iron-based) approaches. Tethering multiple Gd-chelates to a supramolecular platform is a promising strategy to increase r1 relaxivity, as rotational correlation time of the Gd ions can bec...

The simple modification of the hydroxypropyl arm in Gd(HP-DO3A) complex allows to achieve an increased relaxivity by activation intramolecular catalysis proton exchange process.

Gadolinium diethylenetriaminepentaacetic acid (DTPA) has not proved particularly useful for hepatosplenic magnetic resonance imaging. However, by entrapping the Gd-DTPA within lipid vesicles, one may exploit the ability of the reticuloendothelial system to endocytose particulates, permitting passive delivery of contrast agent to the liver and spleen while decreasing the rate of clearance of Gd-...

The 1 H nuclear magnetic resonance (NMR) spin-lattice relaxation rate of hydrated sands is related to the surface-to-volume ratio of the voids or pores between the hydrated sand grains and the surface relaxivity of the grains. The electron spin resonance (ESR) signal is often used to predict the relative surface relaxivity as the surface relaxivity is thought to be proportional to the concentra...

Gadolinium endohedral metallofullerenes (EMFs) have shown the potential to become next generation magnetic resonance imaging (MRI) contrast agents due to their significantly improved efficiency and safety, as well as multi-day body retention which allows for a longer surgery and observation compared to current contrast agents. In Chapter 1, I have reviewed the development of gadolinium EMF base...

Gold nanoparticles functionalized with Gd(3+) chelates displaying fast water exchange, superb pH stability and inertness towards transmetalation with Zn(2+) have been prepared and characterized as a new high relaxivity (29 mM(-1) s(-1), 30 MHz, 25 °C) contrast agent potentially safe for in vivo MRI applications. The Lipari-Szabo treatment for internal rotation was used to evaluate the effect of...

The relaxivity of commercially available gadolinium (Gd)-based contrast agents was studied for X-nuclei resonances with long intrinsic relaxation times ranging from 6 s to several hundred seconds. Omniscan in pure 13C formic acid had a relaxivity of 2.9 mM(-1) s(-1), whereas its relaxivity on glutamate C1 and C5 in aqueous solution was approximately 0.5 mM(-1) s(-1). Both relaxivities allow the...

objective(s):iron oxide nanoparticles have found prevalent applications in various fields including drug delivery, cell separation and as contrast agents. super paramagnetic iron oxide (spio) nanoparticles allow researchers and clinicians to enhance the tissue contrast of an area of interest by increasing the relaxation rate of water. in this study, we evaluate the dependency of hydrodynamic si...

A new Cu(2+)-responsive MRI contrast agent (Gd-QDOTAMA) with a quinoline-based ligand was synthesized and characterized. Relaxivity studies on Gd-QDOTAMA showed that the relaxivity increased from 4.27 mM(-1) s(-1) to 7.29 mM(-1) s(-1) in response to equimolar amounts of copper(II) ion, corresponding to ca. 71% relaxivity enhancement. Distinct changes in relaxivity were undetected upon addition ...

The relaxivity of commercially available gadolinium (Gd)-based contrast agents was studied for X-nuclei resonances with long intrinsic relaxation times ranging from 6 s to several hundred seconds. Omniscan in pure C formic acid had a relaxivity of 2.9 mM 1 s , whereas its relaxivity on glutamate C1 and C5 in aqueous solution was ~0.5 mM 1 s . Both relaxivities allow the preparation of solutions...