Recent Research Progress of ¹⁹F Magnetic Resonance Imaging Probes: Principle, Design, and Their Application

Abstract

Visualization of biomolecules, cells, and tissues, as well as metabolic processes in vivo is significant for studying the associated biological activities. Fluorine magnetic resonance imaging (19F MRI) holds potential among various imaging technologies thanks to its negligible background signal and deep tissue penetration in vivo. To achieve detection on the targets with high resolution and accuracy, requirements of high‐performance 19F MRI probes are demanding. An ideal 19F MRI probe is thought to have, first, fluorine tags with magnetically equivalent 19F nuclei, second, high fluorine content, third, adequate fluorine nuclei mobility, as well as excellent water solubility or dispersity, but not limited to. This review summarizes the research progresses of 19F MRI probes and mainly discusses the impacts of structures on in vitro and in vivo imaging performances. Additionally, the applications of 19F MRI probes in ions sensing, molecular structures analysis, cells tracking, and in vivo diagnosis of disease lesions are also covered in this article. From authors’ perspectives, this review is able to provide inspirations for relevant researchers on designing and synthesizing advanced 19F MRI probes.

Transition metal complexes of cyclam with two 2,2,2-trifluoroethylphosphinate pendant arms as probes for 19F magnetic resonance imaging

“…in monitoring the fate of transplanted cells (cell tracking). [6][7][8] A number of compounds have been tested as 19 F NMR contrast agents. They were usually perfluorinated hydrocarbons † Electronic supplementary information (ESI) available: NMR spectra of studied complexes, colour change of isomeric Cu(II) complexes, experimental data and details for the crystal structure refinement, ligand distribution diagram, details of the kinetic inertness study, NMR characterization of organic compounds, and discussion of the crystal structures of synthetic intermediates.…”

Synthesis and Detection of BODIPY‐, Biotin‐, and 19F‐ Labeled Single‐Entity Dendritic Heparan Sulfate Mimetics

“…However, 1 H MRI suffers from low contrast‐to‐noise ratio due to the large background signal of bulk water in tissues, thus limiting its application for in vivo and ex vivo visualization of chemical probes in biodistribution studies. Consequently, 19 F MRI has emerged as a valuable complement to 1 H MRI, with high contrast images provided due to the absence of endogenous 19 F and 100 % isotopic abundance of 19 F [39–42] . As such, we investigated the potential of 19 F MRI for the detection of HS mimetics, with the aim of determining their biodistribution and tissue localization in in vivo disease models.…”

“…Chemie contrast images provided due to the absence of endogenous 19 F and 100 % isotopic abundance of 19 F. [39][40][41][42] As such, we investigated the potential of 19 F MRI for the detection of HS mimetics, with the aim of determining their biodistribution and tissue localization in in vivo disease models. 18 b was thus prepared, bearing the bis-trifluoromethyl phenyl moiety, previously used for 19 F MRI in vivo imaging.…”

Fluorinated hydrogel nanoparticles with regulable fluorine contents andT2relaxation times as19F MRI contrast agents

“…Beside the mobility of uorine atoms, the uorine content in 19 F MRI CAs also inuence the 19 F NMR intensity and the 19 F MRI imaging behavior. 44 Thus, by adjusting the feed mole ratio of monomer TBA and TFMA in the polymerization process, another four 19 F MRI HNCAs samples with different uorine contents were synthesized by applying the same procedure and conditions as well. Compared with the 19 F MRI HNCAs-1, the uorine contents of the newly synthesized 19 F MRI HNCAs were enhanced with increasing the feed ratio of TFMA in the polymerization.…”

“…36 In order to achieve high performance in 19 F MRI, the inuence of the topological structures (linear, block, hyperbranched, star-like) and nanostructures (micelles, vesicles, and worm-like micelles) of 19 F MRI CAs on the imaging performance have also been explored in depth, [37][38][39][40][41][42][43] because the mobility of the uorine atoms in 19 F MRI CAs is determined by the topological structures, while the uptake and accumulation behavior of the 19 F MRI CAs inside disease lesions are inuenced by their nanostructures. 44,45 For example, Kristofer J. Thurecht et al explored the inuence of the topology structure on the T 2 relaxation times and imaging performance of 19 F MRI CAs by synthesizing a series of hyperbranched polymeric scaffolds. The longest T 2 relaxation time of 71 ms could be obtained by incorporating hydrophilic oligo(ethyl glycol) (M w = 400) in their hyperbranched 19 F MRI CAs.…”