Tumor cells were targeted with Gd-loaded/LDL (low density lipoproteins) adducts consisting of ca 300 Gd(III) amphiphilic complexes incorporated in the lipophilic LDL particles. The long reorientational time of the Gd(III) complex in the supramolecular adduct yielded a relaxivity peak at ca 1 T, whereas its relaxivity at 7 T was 5 times less. The field-dependent relaxivity markedly affected the ...

We have measured the bimolecular contribution (relaxivity) R1 (M(-1) s(-1)) to the spin-lattice relaxation rate for the protons of H2 and H2@C60 dissolved in organic solvents in the presence of paramagnet nitroxide radicals. It is found that the relaxation effect of the paramagnets is enhanced 5-fold in H2@C60 compared to H2 under the same conditions. 13C relaxivity in C60 induced by nitroxide ...

An elevated-temperature polyol-based colloidal-chemistry approach allows for the development of size-tunable (50 and 86 nm) assemblies of maghemite iso-oriented nanocrystals, with enhanced magnetization. (1)H-nuclear magnetic resonance (NMR) relaxometric experiments show that the ferrimagnetic cluster-like colloidal entities exhibit a remarkable enhancement (4-5 times) in transverse relaxivity ...

INTRODUCTION Molecular Imaging of transplanted stem and progenitor cells is essential to understand their therapeutic potential. Stable labeling of cells with either iron oxide particles (USPIO) or lanthanide chelates has proven successful for MRI-based detection of cell deposits and their migration [1, 2]. However, MRI only provides information about the location but not about cellular change ...

Endosome-escapable poly(amino acid) nanoparticles composed of iron oxide nanocrystals and anticancer drugs were prepared and demonstrated high T(2) relaxivity coefficients and higher efficacy attributed to the endosomolytic ability of the conjugated histidine moiety.

We present the synthesis and characterization of octaarginine-conjugated Copper-Gad-2 (Arg8CG2), a new copper-responsive magnetic resonance imaging (MRI) contrast agent that combines a Gd3+-DO3A scaffold with a thioether-rich receptor for copper recognition. The inclusion of a polyarginine appendage leads to a marked increase in cellular uptake compared to previously reported MRI-based copper s...

Mn-based nanoparticles have been regarded as a new class of probes for magnetic resonance imaging (MRI), but their low relaxivity is the major obstacle for applications in vivo. Herein, we designed and constructed a multifunctional nanotheranostic (FA-Mn3O4@PDA@PEG) for MRI guided combinatorial chemo-/photothermal therapy (PTT) for cancer. The ultrahigh relaxivity of 14.47 mM-1 s-1 makes the na...

BACKGROUND AND PURPOSE With the approval of gadobenate dimeglumine, higher relaxivity MR contrast agents were introduced into the clinical environment, and multiple in vivo studies compared the efficacy and safety with the previously approved agents. An in vitro study was conducted to demonstrate differences between the various agents to confirm published values and for imaging-sequence optimiz...