Combination of bioresponsive chelates and perfluorinated lipid nanoparticles enables in vivo MRI probe quantification

Abstract

We developed a nanosized perfluorocarbon-based system with incorporated paramagnetic Gd(III) chelates, able to generate a quantitative 19F MRI signal, while in parallel capable of modulating the 1H MRI signal in...

From Zn(II) to Cu(II) Detection by MRI Using Metal-Based Probes: Current Progress and Challenges

“…A perfluoro-15-crown-5-ether was included in the hydrophobic core of a micelle composed of surfactant and an amphiphilic Gd 3+ complex responsive to Ca 2+ [96]. The system shows a 30% increase in r 1 and a 343% increase in r 2 upon Ca 2+ binding at 7 T and 25 • C. T 1 -, T 2 -and T 2 /T 1 -weighted images were performed first on phantom samples containing different Gd 3+ concentrations and diamagnetic samples of trifluoroacetic acid (TFA) for calibration of the 19 F signal.…”

Metal-based environment-sensitive MRI contrast agents

“…New technologies such as fast-field-cycling MRI have been used to enhance the response at higher field. Finally, other imaging techniques relying on paraCEST, parashift agents, or 19 F MRI have emerged recently for cation detection.…”

“…[18] 19 F NMR was also used to quantify Ca 2+ -responsive Gd 3+ complexes. In a micelle composed of a surfactant and an amphiphilic Gd 3+ complex responsive to Ca 2+ , perfluoro-15-crown-5-ether was incorporated and its 19 F signal used as a reporter of Gd 3+ concentration. [19] First, it was checked that Ca 2+ binding does not affect 19 F MR images, while it leads to a significant increase in 1 H r 1 and r 2 (30 and 343 %, respectively at 7 T and 25 °C).…”

“…Here we survey two specific areas of spectacular progress in the last years: (i) MRI detection of biologically important metal ions, where in vivo applications have been particularly successful, and (ii) smart agents based on transition metal complexes, which is a freshly emerging field in response to toxicity concerns associated with Gd 3+ . In addition to relaxation agents, we will also discuss paramagnetic chemical exchange saturation (paraCEST) and shift (parashift) probes and 19 F MRI detection.…”

Encapsulation of Paramagnetic Chelates in Perfluorcarbon-loaded Fractal Nanoparticles Enables Modulation of Fluorine-19 and Proton Magnetic Resonance Imaging Signal

“…1,2,4,5,21,22 The core sizes are usually at least several 10's of nanometers. 1,2,4,5 As a result of the core-shell structure, currently, there are two strategies for the modification with paramagnetic chelates: (1) covalent attachment or encapsulation of the hydrophilic or hydrophobic chelates in the organic shell of the agent, 12,23,24 and (2) encapsulation of fluorophilic chelates in the fluorous core. [13][14][15]25 When a paramagnetic chelate is encapsulated or covalently bound to the shell, it typically affects only a small fraction of 19 F-nuclei that are close to the shell.…”