Functionalized Gold Nanoparticles as Contrast Agents for Proton and Dual Proton/Fluorine MRI

Abstract

Gold nanoparticles carrying fluorinated ligands in their monolayer are, by themselves, contrast agents for 19F magnetic resonance imaging displaying high sensitivity because of the high density of fluorine nuclei achievable by grafting suitable ligands on the gold core surface. Functionalization of these nanoparticles with Gd(III) chelates allows adding a further functional activity to these systems, developing materials also acting as contrast agents for proton magnetic resonance imaging. These dual mode contrast agents may allow capitalizing on the benefits of 1H and 19F magnetic resonance imaging in a single diagnostic session. In this work, we describe a proof of principle of this approach by studying these nanoparticles in a high field preclinical scanner. The Gd(III) centers within the nanoparticles monolayer shorten considerably the 19F T1 of the ligands but, nevertheless, these systems display strong and sharp NMR signals which allow recording good quality 19F MRI phantom images at nanoparticle concentration of 20 mg/mL after proper adjustment of the imaging sequence. The Gd(III) centers also influence the T1 relaxation time of the water protons and high quality 1H MRI images could be obtained. Gold nanoparticles protected by hydrogenated ligands and decorated with Gd(III) chelates are reported for comparison as 1H MRI contrast agents.

Laser‐induced optothermal response of gold nanoparticles: From a physical viewpoint to cancer treatment application

“…The affordability of US systems and the use of non‐ionizing waves makes this technique appealing for clinical application, despite the motion artifacts and the unexpected variation in acoustic tissue properties. Regarding the use of the mentioned techniques in combination with NPs, several studies have proposed these imaging techniques for evaluating the multimodal contrast‐capability of GNPs [248–250] and other materials [251].…”

Dual Imaging Gold Nanoplatforms for Targeted Radiotheranostics

“…Studies have shown that the synergistic effect of irradiation and gold nanoparticles can lead to a significant tumor reduction. Moreover, the benefit of this combinatory therapy is also strongly dependent on the size, coating, and number of internalized nanoparticles in cancer cells and on the radiation energy [23][24][25][26][27][28][29][30][31][32][33][34]. A few Gd 3+ -based molecules and particles have also been reported, combining MRI guided imaging with radiosensitization.…”

Synthesis and Stabilization of Support-Free Mesoporous Gold Nanoparticles

“…Support-free porous noble metal nanoparticles can conveniently be administered and tracked in biological systems. These properties together with their porosities and optical characteristics form the basis of their biomedical applications, such as drug delivery [ 18 , 19 ], drug-screening [ 20 ], drug encapsulation [ 21 , 22 ], gene delivery [ 23 , 24 , 25 ], photothermal therapy [ 6 , 7 , 8 , 9 , 10 ], diagnostic imaging [ 26 ] and ophthalmological applications [ 27 ]. Furthermore, the biocompatibility of gold nanoparticles has also been confirmed by numerous cytotoxicity studies [ 28 , 29 ].…”