NaGdF₄ Nanoparticle-Based Molecular Probes for Magnetic Resonance Imaging of Intraperitoneal Tumor Xenografts in Vivo

Abstract

Differently sized NaGdF(4) nanocrystals with narrow particle size distributions were synthesized by a high temperature approach. Upon ligand exchange, the as-prepared hydrophobic NaGdF(4) nanocrystals were transferred into water by using asymmetric PEGs simultaneously bearing phosphate and maleimide groups. Further investigations demonstrated that the water-soluble NaGdF(4) nanocrystals, coated by PEG bearing two phosphate groups on the same side, exhibit not only excellent colloidal stability in water and PBS buffer, but also higher T1 relaxivity than Gd-DTPA (Magnevist). Through "click" reaction between the maleimide residue on particle surface and thiol group from the partly reduced anti-EGFR monoclonal antibody (mAb), NaGdF(4)-PEG-mAb nanoprobes were constructed, and their biocompatibility and binding specificity were evaluated through in vitro experiments. A series of in vivo experiments were then carried out for detecting intraperitoneal tumor xenografts in nude mice by using magnetic resonance (MR) imaging technique. The results revealed that the NaGdF(4)-PEG-mAb probes possessed satisfying tumor-specific targeting ability and strong MR contrast enhancement effects.

Size Control of Nearly Monodisperse β-NaGdF4 Particles Prepared from Small α-NaGdF4 Nanocrystals

“…Nanoparticles based on the NaGdF 4 host lattice are being investigated for a variety of applications such as magnetic resonance imaging (MRI) [1][2][3][4][5][6][7][8][9] , multimodal biological labelling/sensing and imaging, 10-21 photodynamic therapy, 10,[22][23][24] spectral conversion in solar cells, 25,26 and nanothermometers. 27,28 NaGdF 4 and other NaREF 4 nanocrystals (RE = rare earth) are often prepared in oleic acid based solvent mixtures yielding very narrow particle size distributions.…”

Flow Synthesis of Biocompatible Fe3O4 Nanoparticles: Insight into the Effects of Residence Time, Fluid Velocity, and Tube Reactor Dimension on Particle Size Distribution

“…1,2 Further driven by increasingly widespread biomedical applications in molecular imaging of tumors, 1−3 cancer drug carriers, 2,4 and hyperthermia treatment, 5 immense studies on delicate control over the particle size and size distribution of iron oxide nanoparticles and their biocompatible surface modification have been carried out, 1−3,6 because these parameters strongly determine the physiochemical properties of magnetic nanoparticles and their pharmacokinetic behaviors as well. 7,8 Thermal decomposition synthesis, through the pyrolysis of Fe organometallic precursors, has been demonstrated to be the most effective approach for achieving high quality iron oxide nanoparticles. 9−11 However, it is widely investigated so far based on batch preparation.…”

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

“…This hypothesis explains the general observation consisting in the increase of r1 value with increasing the surface/volume (S/V) ratio [308][309][310]. For example, increasing relaxivity r1 values from 2.34 mm [312]. This result has been explained by the contribution of the tumbling time of the NP, which increases as the NP size increases, counteracting the effect of the S/V ratio on the relaxivity [304].…”