Surface modified Eu:GdVO4 nanocrystals for optical and MRI imaging

Abstract

A facile solvothermal route has been developed for the preparation of europium doped gadolinium orthovanadate nanoparticles (∼70 nm) with tetragonal structure, based on a homogenous precipitation reaction at 120°C from rare earth precursors (yttrium nitrate and europium nitrate) and sodium orthovanadate solutions using an ethylene glycol-water mixture as the solvent. The effects of the doping level on the luminescence properties were evaluated in order to find the optimum nanophosphors. These nanocrystals were successfully functionalized with amino (two step process) and carboxylate (one-pot process) groups provided by amino-dextran polymers (AMD) and polyacrylic acid (PAA), respectively. It was found that while the luminescent properties of both kinds of functionalized systems were similar, the colloidal stability of the PAA-modified sample was higher, because of which, it was selected to study their cytotoxicity and magnetic properties (relaxivity and phantom analyses) to assess their potentiality as multifunctional probes for both "in vitro" optical biolabels and negative contrast agents for magnetic resonance imaging.

Synthesis, photophysical analysis, and in vitro cytotoxicity assessment of the multifunctional (magnetic and luminescent) core@shell nanomaterial based on lanthanide-doped orthovanadates

“…Despite the importance of vanadates doped with lanthanide ions, only a few studies concerned their utilization in biology and medical science (Cheng et al 2012;Shanta Singh et al 2013;Wang et al 2009), whereas some of the research showed that Ln:GdVO 4 nanoparticles (NPs) may have potential application in optical or MRI images (Huang et al 2013;Nuñez et al 2013;Kang et al 2013a;Yin et al 2012). In addition, combination of magnetic and luminescent properties of nanoparticles makes them particularly useful.…”

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

“…In addition to an excellent contrast enhancement, Ln-based NPs present long circulating times and are easy to functionalize, which make them an interesting alternative to the traditionally used Gd chelate CAs commented on above. A large variety of them, ranging from oxides [302] to fluorides [303,304] and sulfides [305], as well as Gd oxysalts [44,64,180,306], have been synthesized and demonstrated good ability as T1 CAs. In many cases, an even higher level of image resolution was shown with the use of Ln-based NPs than with Gd chelates.…”

“…The one-pot strategy does not work for all systems, and other functionalization procedures carried out as a second step following the NPs synthesis have been developed. These procedures take place via electrostatic or chemical interactions and have been used to functionalize GdF 3 :Eu 3+ , GdVO 4 :Eu 3+ and NaGd(MoO 4 ) 2 :Eu 3+ NPs with aspartic-dextran [54], aminodextran [64] and poly(L-lysine) [89], respectively. An interesting method for the functionalization of previously synthesized NPs is the layer-by-layer (LbL) technique.…”

Immuno-silent polymer capsules encapsulating nanoparticles for bioimaging applications

“…Since, cytokines are the primary molecules of immune response, the evaluation of cytokine levels are used as biomarkers for understanding immune modulation by nanomaterials. 13 19,20 In our recent reports, these polymer capsules encapsulating nanoparticles were demonstrated as biocompatible at both in vitro at in vivo levels. 16,21 Since, they possess good imaging properties along with biocompatibility and efficient internalization, it is essential to study their immune response.…”