We report the modular formulation of ciprofloxacin-based pure theranostic nanodrugs that display enhanced antibacterial activities, as well as aggregation-induced emission (AIE) enhancement that was successfully used to image bacteria. The drug derivatives, consisting of ciprofloxacin, a perfluoroaryl ring, and a phenyl ring linked by an amidine bond, were efficiently synthesized by a straightforward protocol from a perfluoroaryl azide, ciprofloxacin, and an aldehyde in acetone at room temperature. These compounds are propeller-shaped, and upon precipitation into water, readily assembled into stable nanoaggregates that transformed ciprofloxacin derivatives into AIE-active luminogens. The nanoaggregates displayed increased luminescence and were successfully used to image bacteria. In addition, these nanodrugs showed enhanced antibacterial activities, lowering the minimum inhibitory concentration (MIC) by more than one order of magnitude against both sensitive and resistant Escherichia coli. The study represents a strategy in the design and development of pure theranostic nanodrugs for combating drug-resistant bacterial infections.nanodrugs | aggregation-induced emission | fluoroquinolones
RAFT copolymerization of 4-[(hydroxyimino)aldehyde]butyl methacrylate with OEGMA475 and first assessment of photoisomerization and thermal behavior of the copolymers in solution.
Molecules, capable of fluorescence turn-on by light, are highly sought-after in spatio-temporal labeling, surface patterning, monitoring cellular and molecular events, and high-resolution fluorescence imaging. In this work, we report a fluorescence turn-on system based on photoinitiated intramolecular C-H insertion of azide into the neighboring aromatic ring. The azide-masked fluorogens were efficiently synthesized via a cascade nucleophilic aromatic substitution of perfluoroaryl azides with carbazoles. The scaffold also allows for derivatization with biological ligands, as exemplified with D-mannose in this study. This photoinitiated intramolecular transformation led to high yields, high photo-conversion efficiency, and wellseparated wavelengths for photoactivation and fluorescence excitation. The mannose-derivatized structure enabled spatio-temporal activation and showed high contrast and signal amplification. Live cell imaging suggested that the mannose-tagged fluorogen was transported to the lysosomes.
A new conjugation method for the immobilization of carbohydrates on nanomaterials was demonstrated simply by mixing perfluorophenyl azide-functionalized silica nanoparticles (SNPs), an amine-derivatized carbohydrate, and phenylacetaldehyde under ambient conditions without any catalyst. The density of carbohydrates on the glyconanoparticles was determined using the quantitative F NMR (F qNMR) technique; for example, the density of d-mannose (Man) on Man-SNPs was 2.5 ± 0.2 × 10 nmol/nm. The glyconanoparticles retained their binding affinity and selectivity toward cognate lectins. The apparent dissociation constant of the glyconanoparticles was measured by a fluorescence competition assay, where the binding affinity of Man-SNPs was almost 4 orders of magnitude higher than that of Man with concanavalin A. Moreover, even with a ligand density of 2.6 times lower than Man-SNPs synthesized by the copper-catalyzed azide-alkyne cycloaddition, the binding affinity of Man-SNPs prepared by the current method was more than 4 times higher.
Sulfonimidamides
(SIAs) and sulfoximines (SOIs) have attracted
attention due to their potential in agriculture and in medicinal chemistry
as bioisosteres of biologically active compounds, and new synthetic
methods are needed to access and explore these compounds. Herein,
we present a light-promoted generation of perfluorinated aromatic
nitrenes, from perfluorinated azides, that subsequently are allowed
to react with sulfinamides and sulfoxides, generating achiral and
chiral SIAs and SOIs. One of the enantiopure SIAs was evaluated as
a novel chiral auxiliary in Grignard additions to the imines yielding
the product in up to 96:4 diastereomeric ratio.
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