A Library of Fluorinated Electrophiles for Chemical Tagging and Materials Synthesis

Sulfobetaine Zwitterions with Embedded Fluorocarbons: Synthesis and Interfacial Properties

We describe the preparation of a new set of fluorinated sulfobetaine (FSB) zwitterionic polymers in which fluorocarbon moieties are attached directly to the zwitterionic components. An efficient two-step modification to the conventional sulfobetaine methacrylate monomer synthesis gave access to a series of polymer zwitterions containing varying extents of fluorocarbon character. FSB methacrylates proved amenable to homo- and copolymerizations using reversible addition-fragmentation chain transfer (RAFT) conditions, affording polymers with molecular weights ranging from 5 to 20 kDa and with low molecular weight distributions. Thin films of FSB homopolymers on glass proved stable to aqueous environments and exhibited increasing hydrophobicity with fluorocarbon content, as well as remarkably large water contact angle hysteresis values that enable pinning of water droplets on hydrophobic surfaces, reminiscent of the "petal effect" found in nature. FSB-containing copolymers in aqueous media demonstrated markedly reduced oil-water interfacial tension values, even with moderate (20-50 mol %) FSB incorporation.

Perfluoro-tert-butyl Group-Derived Capmatinib: Synthesis, Biological Evaluation and Its Application in 19 F Magnetic Resonance Imaging

Capmatinib is an FDA-approved drug to treat metastatic non-small cell lung cancer with MET-exon 14 skipping. Herein, the perfluoro-tert-butyl group, which possesses nine chemically identical fluorine atoms, was introduced on Capmatinib to afford a targeted 19 F magnetic resonance imaging (MRI) probe, perfluoro-tert-butyl group-derived Capmatinib (9F-CAP). The 19 F MRI concentration limit was found to be 25 mM in FLASH sequence. Molecular docking simulation, surface plasmon resonance (SPR) (with a Kd of 40.7 μM), half-inhibitory concentration (with a IC50 of 168 nM), Annexin V, and cytotoxicity assays jointly demonstrated that the 9F-CAP targeted cMET protein specifically. Therefore, the targeted imaging capability of 9F-CAP is of great significance for the preoperative diagnosis of specific cancers.

Amphiphilic Polyfluorinated Amino Ethers from Cyclic Sulfamidates

Regioselective ring opening of cyclic sulfamidates was achieved by means of nucleophilic polyfluorinated alkoxides to access achiral and chiral β- and γ-OR^F amines and α-amino esters. Subsequent transformations provide free amines ready for incorporation into bioactive substances through amide bond formation or nucleophilic aromatic substitution.

Highly Fluorinated Peptide Probes with Enhanced In Vivo Stability for 19 F-MRI

A labeling strategy for in vivo ¹⁹ F-MRI (magnetic resonance imaging) based on highly fluorinated, short hydrophilic peptide probes, is developed. As dual-purpose probes, they are functionalized further by a fluorophore and an alkyne moiety for bioconjugation. High fluorination is achieved by three perfluoro-tert-butyl groups, introduced into asparagine analogues by chemically stable amide bond linkages. d-amino acids and β-alanine in the sequences endow the peptide probes with low cytotoxicity and high serum stability. This design also yielded unstructured peptides, rendering all 27 ¹⁹ F substitutions chemically equivalent, giving rise to a single ¹⁹ F-NMR resonance with <10 Hz linewidth. The resulting performance in ¹⁹ F-MRI is demonstrated for six different peptide probes. Using fluorescence microscopy, these probes are found to exhibit high stability and long circulation times in living zebrafish embryos. Furthermore, the probes can be conjugated to bovine serum albumin with only amoderate increase in ¹⁹ F-NMR linewidth to ≈30 Hz. Overall, these peptide probes are hence suitable for in vivo ¹⁹ F-MRI applications.

Fluorinated Polymer Zwitterions: Choline Phosphates and Phosphorylcholines

Among zwitterionic structures, the choline phosphate (CP) group is uniquely attractive for its ability to access novel chemical compositions that embed functional groups directly into the zwitterionic moiety. This paper describes the attachment of fluorinated alkyl groups to CP moieties, yielding zwitterionic monomers 1 and 2 that proved amenable to controlled free radical polymerization and the production of a new set of CP-containing fluorinated polymers and copolymers with phosphorylcholine (PC) zwitterions. This combination of fluorinated hydrocarbons and zwitterions affords novel, water-soluble polymeric amphiphiles that we have examined at fluid interfaces, as coatings, in cell culture, and in magnetic resonance imaging.

Perfluoro-tert-butanol: a cornerstone for high performance fluorine-19 magnetic resonance imaging

As a versatile quantification and tracking technology, 19F magnetic resonance imaging (19F MRI) provides quantitative "hot-spot" images without ionizing radiation, tissue depth limit, and background interference. However, the lack of suitable imaging agents severely hampers its clinical application. First, because the 19F signals are solely originated from imaging agents, the relatively low sensitivity of MRI technology requires high local 19F concentrations to generate images, which are often beyond the reach of many 19F MRI agents. Second, the peculiar physicochemical properties of many fluorinated compounds usually lead to low 19F signal intensity, tedious formulation, severe organ retention, etc. Therefore, the development of 19F MRI agents with high sensitivity and with suitable physicochemical and biological properties is of great importance. To this end, perfluoro-tert-butanol (PFTB), containing nine equivalent 19F and a modifiable hydroxyl group, has outperformed most perfluorocarbons as a valuable building block for high performance 19F MRI agents. Herein, we summarize the development and application of PFTB-based 19F MRI agents and analyze the strategies to improve their sensitivity and physicochemical and biological properties. In the context of PFC-based 19F MRI agents, we also discuss the challenges and prospects of PFTB-based 19F MRI agents.

Fluoropolymers in biomedical applications: state-of-the-art and future perspectives

Biomedical applications of fluoropolymers in gene delivery, protein delivery, drug delivery, ¹⁹F MRI, PDT, anti-fouling, anti-bacterial, cell culture, and tissue engineering.