Bacterial β sliding clamp (β-clamp) is an emerging drug target currently lacking small-molecule inhibitors with good in vivo activity. Thus, there is a need for fast and simple screening methods for identifying inhibitor candidates. Here we demonstrate the use of nuclear magnetic resonance spectroscopy (NMR) for evaluating compound binding to the E. coli β-clamp. To identify suitable molecular probes, a series of tetrahydrocarbazoles were synthesized, some of which contain fluorine. Key challenges in the synthesis were formation of regioisomers during the Fischer indole reaction and reducing racemization at the stereogenic center. The tetrahydrocarbazoles were assayed against the E. coli β-clamp by saturation-transfer difference (STD) NMR, waterLOGSY and T1ρ. Analysis by isothermal titration calorimetry gave KD-values of 1.7-14 μM for three fluorinated probe candidates, and NMR chemical shift perturbation experiments confirmed these molecules to directly interact with the β-clamp binding pocket. Binding of the fluorinated molecules to β-clamp was easily observed with 19F-observed T2-based binding experiments, and proof of concept for a fluorine-based binding assay for E. coli β-clamp binders is provided.
- MeSH
- Escherichia coli * drug effects MeSH
- Halogenation MeSH
- Carbazoles * chemistry chemical synthesis pharmacology metabolism MeSH
- Magnetic Resonance Spectroscopy * MeSH
- Molecular Probes chemistry chemical synthesis metabolism MeSH
- Molecular Structure MeSH
- Escherichia coli Proteins metabolism antagonists & inhibitors chemistry MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Structure-Activity Relationship MeSH
- Publication type
- Journal Article MeSH
Chlorinated paraffins (CPs) are environmental pollutants extensively used in industries. While the use of short-chain chlorinated paraffins (SCCPs) has been restricted since 2017, the use of medium-chain chlorinated paraffins (MCCPs) has risen as their replacement. Due to lipophilic character, it can be expected that CPs enter the cells; however, the in vitro accumulation potential of CPs remains poorly understood. In this study, we aimed to explore the ability of SCCPs and MCCPs to accumulate in fat cells. We utilized an in vitro model of mouse 3T3-L1 preadipocytes and adipocytes. Using gas chromatography coupled with high-resolution mass spectrometry operated in negative chemical ionization mode, we determined the intracellular amounts of CPs. These compounds accumulated at rates of 8.5 ± 0.1 μg/gcells/h for SCCPs and 7.8 ± 0.3 μg/gcells/h for MCCPs when an initial concentration of 120 ng/ml was present in the medium. This rate increased approximately tenfold when the concentration of CPs was raised to 1200 ng/ml. CPs content in adipocytes steadily increased over 5 days, whereas preadipocytes accumulated 15-20 times less CPs. This highlights the importance of cellular lipid content, which was about 12 times higher in adipocytes. Furthermore, we found that the level of chlorine content in the CPs molecules significantly influenced their accumulation. Our results demonstrate that MCCPs exhibit a similar accumulation potential to SCCPs, with lipid content playing a crucial role. As with SCCPs, restrictions on the use of MCCPs in industry should be considered to mitigate their environmental and health impacts.
- MeSH
- 3T3-L1 Cells * MeSH
- Hydrocarbons, Chlorinated * metabolism toxicity MeSH
- Halogenation * MeSH
- Environmental Pollutants toxicity metabolism MeSH
- Lipid Metabolism drug effects MeSH
- Mice MeSH
- Paraffin * MeSH
- Gas Chromatography-Mass Spectrometry MeSH
- Adipocytes * metabolism drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The aryl hydrocarbon receptor (AhR) is a cytosolic ligand-activated transcription factor integral to various physiological and pathological processes. Among its diverse ligands, indole-based compounds have garnered attention due to their significant biological activity and potential therapeutic applications. This study explores the activation of AhR by structurally diverse halogenated indoles. We evaluated the transcriptional activity of AhR and cell viability in the human LS174T-AhR-luc reporter cell line. Among the tested compounds, 4-FI, 7-FI, 6-BrI, 7-BrI, 6-Cl-2-ox, 5-Br-2-ox, and 6-Br-2-ox activated AhR in a concentration-dependent manner, displaying high efficacy and potency. Molecular docking analysis revealed moderate binding affinities of these compounds to the PAS-B domain of AhR, corroborated by competitive radioligand binding assays. Functional assays showed that halogenated indoles induce the formation of AhR-ARNT heterodimer and enhance the binding of the AhR to the CYP1A1 promoter. Additionally, 4-FI and 7-FI exhibited anti-inflammatory properties in Caco-2 cell models, highlighting their potential for therapeutic applications. This study underscores the significance of the type and position of halogen moiety in indole scaffold, suggesting their potential as candidates for developing therapeutics drugs to treat conditions such as inflammatory bowel disease via AhR activation.
- MeSH
- Cytochrome P-450 CYP1A1 metabolism MeSH
- Halogenation MeSH
- Indoles * chemistry pharmacology MeSH
- Humans MeSH
- Molecular Structure MeSH
- Receptors, Aryl Hydrocarbon * metabolism chemistry MeSH
- Molecular Docking Simulation * MeSH
- Basic Helix-Loop-Helix Transcription Factors MeSH
- Cell Survival drug effects MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Magnetic resonance imaging (MRI) relies on appropriate contrast agents, especially for visualizing transplanted cells within host tissue. In recent years, compounds containing fluorine-19 have gained significant attention as MRI probe, particularly in dual 1H/19F-MR imaging. However, various factors affecting probe sensitivity, such as fluorine content and the equivalency of fluorine atoms, must be considered. In this study, we synthesized fluorinated micelles with adjustable surface positive charge density and investigated their physicochemical properties and MRI efficacy in phantoms and labeled cells. While the micelles exhibited clear signals in 19F-MR spectra and imaging, the concentrations required for MRI visualization of labeled cells were relatively high, adversely affecting cell viability. Despite their favourable physicochemical properties, achieving higher labeling rates without compromising cell viability during labeling remains a challenge for potential in vivo applications.
- MeSH
- Staining and Labeling methods MeSH
- Phantoms, Imaging MeSH
- Fluorine chemistry MeSH
- Halogenation MeSH
- Cations * chemistry MeSH
- Contrast Media chemistry MeSH
- Humans MeSH
- Magnetic Resonance Imaging methods MeSH
- Micelles * MeSH
- Mice MeSH
- Cell Survival * drug effects MeSH
- Fluorine-19 Magnetic Resonance Imaging methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Theranostics is a novel paradigm integrating therapy and diagnostics, thereby providing new prospects for overcoming the limitations of traditional treatments. In this context, perfluorocarbons (PFCs) are the most widely used tracers in preclinical fluorine-19 magnetic resonance (19F MR), primarily for their high fluorine content. However, PFCs are extremely hydrophobic, and their solutions often display reduced biocompatibility, relative instability, and subpar 19F MR relaxation times. This study aims to explore the potential of micellar 19F MR imaging (MRI) tracers, synthesized by polymerization-induced self-assembly (PISA), as alternative theranostic agents for simultaneous imaging and release of the non-steroidal antileprotic drug clofazimine. In vitro, under physiological conditions, these micelles demonstrate sustained drug release. In vivo, throughout the drug release process, they provide a highly specific and sensitive 19F MRI signal. Even after extended exposure, these fluoropolymer tracers show biocompatibility, as confirmed by the histological analysis. Moreover, the characteristics of these polymers can be broadly adjusted by design to meet the wide range of criteria for preclinical and clinical settings. Therefore, micellar 19F MRI tracers display physicochemical properties suitable for in vivo imaging, such as relaxation times and non-toxicity, and high performance as drug carriers, highlighting their potential as both diagnostic and therapeutic tools.
- MeSH
- Biocompatible Materials chemistry MeSH
- Fluorine chemistry MeSH
- Fluorocarbons chemistry MeSH
- Halogenation MeSH
- Humans MeSH
- Magnetic Resonance Imaging methods MeSH
- Micelles MeSH
- Mice MeSH
- Nanoparticles * chemistry therapeutic use MeSH
- Theranostic Nanomedicine * MeSH
- Fluorine-19 Magnetic Resonance Imaging * methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
We developed a multifunctional polymer coating for nanoparticles (NPs) that enables simultaneous detection by 19F MRI and shielding from blood plasma fouling. The coating is based on a water-soluble fluorinated poly(N-(2-fluoroethyl)acrylamide) (PFEAM) that shows high 19F MRI sensitivity, cytocompatibility and excellent antifouling properties, significantly outperforming polyethylene glycol. A proof-of-concept experiment was performed by synthesizing polymer-coated gold NPs that were successfully visualized by 19F MRI at magnetic fields close to the fields used in clinical practice. This universal approach can be used for coating and tracing of various NPs upon suitable polymer chain-end modification.
- MeSH
- Acrylic Resins chemistry pharmacology MeSH
- Coated Materials, Biocompatible chemistry pharmacology MeSH
- Biofouling prevention & control MeSH
- Fluorine MeSH
- Halogenation MeSH
- Humans MeSH
- Magnetic Resonance Imaging * MeSH
- Nanostructures chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Pancreatic ductal adenocarcinoma (PDAC) is a growing medical problem associated with extensive metastasis and high mortality. Intraperitoneal (IP) administration of therapeutics promises to help the treatment of cancers originated from organs in the peritoneal cavity. In this study, we evaluated how physicochemical properties of self-assembled polycation/siRNA nanoparticles affect their IP delivery efficacy in an orthotopic PDAC model. We have examined the effect of covalent polycation modification with lipophobic and hydrophobic tetrafluoro-p-toluic acid (TFTA), hydrophobic cholesterol, and hydrophilic poly(ethylene glycol) respectively. The surface charge of the three different nanoparticles was also modulated by coating the surface with serum albumin. We found that positively charged fluorine-containing particles with lipophobic properties based on a mixture of positively charged polymeric AMD3100 CXCR4 antagonist (PAMD) and PAMD modified with TFTA (mPAMD-TFTA)/siRNA displayed the best cell uptake and transfection efficacy in vitro. Biodistribution evaluation of the nanoparticles in a syngeneic orthotopic PDAC model revealed that the fluorine-containing formulation also achieved the highest PDAC tumor accumulation after IP administration. With a combination of CXCR4 inhibition by PAMD and PLK1 downregulation by siRNA, the treatment with mPAMD-TFTA/siPLK1 showed significant inhibition of both primary and metastatic PDAC tumors. Overall, our study provides insights into and guides the design of the nanoparticles for improved IP delivery of siRNA in PDAC.
- MeSH
- Halogenation * MeSH
- Humans MeSH
- RNA, Small Interfering MeSH
- Cell Line, Tumor MeSH
- Pancreatic Neoplasms * drug therapy MeSH
- Polyelectrolytes MeSH
- Tissue Distribution MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Over the past two decades, the use of nanoscale zero-valent iron (nZVI) has emerged as a standard method of contaminated groundwater remediation. The effectiveness of this method depends on key intrinsic hydrogeological parameters, which can affect both reactivity of the nanoparticles and their migration in the aquifer. In the case of low hydraulic permeability, the migration of nanoparticles is limited, which negatively influences remediation. An application of nZVI reinforced with a DC electric field led to a significant increase in the efficiency of remediation, as demonstrated by long-term monitoring at a former industrial site in Horice (Czech Republic). For the method testing, a 12 × 9 m polygon was defined around well IS4, where the original contamination was predominantly composed of DCE (7300 μg/l), and with a total concentration of chlorinated ethenes of 8880 μg/l. During the first stage of the activities, 49 kg of nZVI was injected and monitored for two years. Subsequently, the electrodes were installed, and for three years, the synergistic action of nZVI within an applied DC field was monitored. Based on 32 monitoring campaigns performed over the six years, the combined method was compared with an application of the only nZVI in technical, environmental and economic terms. Technically, the method requires annual reinstallation of anodes as a result of their oxidative disintegration. Environmentally, the method provides significantly improved chlorinated ethane reduction, remediation of low permeable zones, and extended efficiency. Economically, the method is five times cheaper when compared to the nZVI used alone.
- MeSH
- Water Pollutants, Chemical analysis chemistry MeSH
- Ethylenes analysis chemistry MeSH
- Halogenation MeSH
- Metal Nanoparticles chemistry MeSH
- Groundwater MeSH
- Environmental Restoration and Remediation * MeSH
- Iron MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
A new method was developed for the mild and selective bromination of simple aromatic compounds and flavonoids in good yields using α,β-dibromohydrocinnamic acid in the presence of a base. This procedure enables selective mono- or dibromination of compounds highly sensitive to oxidative or radical attack. New brominated derivatives of silymarin flavonolignans and related flavonoids were prepared. These brominated derivatives can be used as valuable synthetic intermediates in further synthesis.
A series of new 3,6,9-trisubstituted acridine derivatives with fluorine substituents on phenyl ring were synthesized and their interaction with calf thymus DNA was investigated. Analysis using UV-Vis absorbance spectra provided valuable information about the formation of the acridine-DNA complex. In addition, compounds 8b and 8d were found to display an increased binding affinity (K = 2.32 and 2.28 × 106 M-1, respectively). Topo I/II inhibition mode assays were also performed, and the results verify that the novel compounds display topoisomerase I and II inhibitory activity; compounds 8a, 8b and 8c completely inhibited topoisomerase I activity at a concentration of 60 × 10-6 M, but only compound 8d showed partial ability to inhibit topoisomerase II at concentrations of 30 and 50 × 10-6 M. The ability of the derivatives to impair cell proliferation was tested through an analysis of cell cycle distribution, quantification of cell number, viability studies, metabolic activity measurement and clonogenic assay. The content and localization of the derivatives in cells were analyzed using flow cytometry and fluorescence microscopy. The compounds 8b and 8d altered the physiochemical properties and improved antiproliferative activity in A549 human lung carcinoma cells (compound 8d displayed the highest level of activity, 4.25 × 10-6 M, after 48 h).
- MeSH
- Acridines chemical synthesis chemistry pharmacology MeSH
- A549 Cells MeSH
- DNA Topoisomerases, Type I metabolism MeSH
- DNA Topoisomerases, Type II metabolism MeSH
- DNA drug effects MeSH
- Halogenation MeSH
- Topoisomerase I Inhibitors chemical synthesis chemistry pharmacology MeSH
- Topoisomerase II Inhibitors chemical synthesis chemistry pharmacology MeSH
- Humans MeSH
- Molecular Structure MeSH
- Cell Proliferation drug effects MeSH
- Antineoplastic Agents chemical synthesis chemistry pharmacology MeSH
- Drug Screening Assays, Antitumor MeSH
- Cattle MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
