Gd-functionalised Aunanoparticles as targeted contrast agents in MRI: relaxivity enhancement by polyelectrolyte coating

Abstract

Monolayer-protected, Gd(3+)-functionalised gold nanoparticles with enhanced spin-lattice relaxivity (r(1)) were prepared; adsorption of polyelectrolytes on these materials further increased r(1) and ligand exchange with a biotin-derivatised disulfide led to a prototype avidin-targeted contrast agent.

Substitution of La and Fe with Dy and Mn in multiferroic La1−xDyxFe1−yMnyO3 nanocrystallites

“…This increase in M s and M r is presumably due to replacement of La, which is diamagnetic (with zero unpaired electrons) with Dy, a highly magnetic moment lanthanide with five unpaired electrons in f-orbital. Although Gd is the elements in the periodic table which possess seven unpaired electrons in Gd 3 þ oxidation state, Dy 3 þ with five unpaired electrons exhibit the maximum magnetic moment, which is due to orbital moment contributions to the actual electronic magnetic moment [24][25].…”

MRI with Gadolinium‐Based Nanoparticles

“…In vivo studies highlighted the potential of these particles as blood pool agents without undesirable accumulation in the lungs, spleen, or liver [162]. They have also been derivatized for targeting by means of antibodies [164], biotin [165], or dnA for cellular uptake [166].…”

Gold nanoparticles functionalised with fast water exchanging Gd3+ chelates: linker effects on the relaxivity

“…10 The "nanotechnology revolution" is underway with a dramatic impact in many fields, particularly in medical imaging. [16][17][18]21,22 Helm and co-workers reported very high relaxivity per chelate immobilized onto AuNPs (60 mM −1 s −1 ; 30 MHz, 25°C), attributed to two exchanging inner sphere water molecules in Gd(DTTA)type chelates and complete rigidity of the chelates immobilized via a short aromatic linker. have found many applications in chemistry, medicine, biotechnology, and other fields owing to intrinsic reporting properties (localized surface plasmon resonance, fluorescence, and X-ray attenuation) 12 coupled to therapeutic properties (hyperthermia and X-ray sensitization), 13 biocompatibility and safety in vivo 14 and facile preparation with tunable size and surface properties by bottom-up methodologies.…”