Search results for "HILIC"

showing 10 items of 745 documents

Amphiphilic Polyphenylene Dendron Conjugates for Surface Remodeling of Adenovirus 5

2020

Abstract Amphiphilic surface groups play an important role in many biological processes. The synthesis of amphiphilic polyphenylene dendrimer branches (dendrons), providing alternating hydrophilic and lipophilic surface groups and one reactive ethynyl group at the core is reported. The amphiphilic surface groups serve as biorecognition units that bind to the surface of adenovirus 5 (Ad5), which is a common vector in gene therapy. The Ad5/dendron complexes showed high gene transduction efficiencies in coxsackie‐adenovirus receptor (CAR)‐negative cells. Moreover, the dendrons offer incorporation of new functions at the dendron core by in situ post‐modifications, even when bound to the Ad5 sur…

Surface (mathematics)DendrimersCell SurvivalPolymersSurface PropertiesvirusesProtein CoronaCHO CellsGene delivery010402 general chemistry01 natural sciencesCatalysisAdenoviridaeTransduction (genetics)CricetulusCricetinaeDendrimerAmphiphilegene technologyAnimalsvirusesResearch ArticlesamphiphilesCycloaddition Reaction010405 organic chemistryChemistryBlood ProteinsGeneral MedicineGeneral ChemistryDendrimers | Hot PaperCombinatorial chemistryproteins0104 chemical sciencesLiposomesHydrophobic and Hydrophilic InteractionsBlood streamResearch ArticleProtein BindingConjugateAngewandte Chemie International Edition
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Size influences the effect of hydrophobic nanoparticles on lung surfactant model systems

2013

Item does not contain fulltext The alveolar lung surfactant (LS) is a complex lipid protein mixture that forms an interfacial monolayer reducing the surface tension to near zero values and thus preventing the lungs from collapse. Due to the expanding field of nanotechnology and the corresponding unavoidable exposure of human beings from the air, it is crucial to study the potential effects of nanoparticles (NPs) on the structural organization of the lung surfactant system. In the present study, we investigated both, the domain structure in pure DPPC monolayers as well as in lung surfactant model systems. In the pure lipid system we found that two different sized hydrophobic polymeric nanopa…

Systems BiophysicsPhase transitionPulmonary Surfactant-Associated ProteinsMaterials science12-DipalmitoylphosphatidylcholineSwineVesicleBiophysicstechnology industry and agricultureNanoparticleMembranes ArtificialNanotechnologyBiological membraneModels BiologicalPhase TransitionSurface tensionPulmonary surfactantChemical engineeringPhase (matter)MonolayerAnimalsNanoparticlesHydrophobic and Hydrophilic InteractionsNanomedicine Radboud Institute for Molecular Life Sciences [Radboudumc 19]
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Asymmetric tandem reactions: New synthetic strategies

2010

The use of domino and multicomponent reactions in asymmetric synthesis is constantly increasing nowadays. This allows for the synthesis of complex molecules in a single synthetic sequence, usually with high atom economy. Herein, we report three examples of new asymmetric tandem reactions recently developed in our laboratories, giving rise to new families of enantiomerically enriched fluorinated and nonfluorinated heterocycles. Thus, 1,4-dihydropyridines (1,4-DHPs) bearing fluorinated substituents at C6 were assembled by means of a Hantzsch-type reaction; cyclic β-amino carbonyl derivatives were prepared using a cross-metathesis (CM)–intramolecular aza-Michael sequence; while fluorinated ind…

TandemChemistryGeneral Chemical EngineeringEnantioselective synthesisSequence (biology)General Chemistrycyclic beta-amino carbonyl compoundElectrophilic aromatic substitutionCombinatorial chemistryDominoNucleophilefluorinated beta-amino acidsAtom economyMoleculeOrganic chemistrytandem reactionsfluorinated dihydropyridinefluorinated indolines
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ChemInform Abstract: ortho-Functionalized Aryltetrazines by Direct Palladium-Catalyzed C-H Halogenation: Application to Fast Electrophilic Fluorinati…

2016

A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-fluorination of tetrazines. Microwave irradiation was optimized to afford fluorinated s-aryltetrazines, with satisfactory selectivity, within only ten minutes. This work provides an efficient and practical entry for further accessing highly substituted tetrazine derivatives (iodo, bromo, chloro, fluoro, and acetate precursors). It gives access to …

Tetrazinechemistry.chemical_compoundchemistryElectrophileElectrophilic fluorinationHalogenationchemistry.chemical_elementSurface modificationGeneral MedicineSelectivityCombinatorial chemistryCatalysisPalladiumChemInform
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Synthesis and mesomorphism of related series of triphilic ionic liquid crystals based on 1,2,4-triazolium cations

2021

Abstract The synthesis, liquid crystal and conductivity properties of a series of 27 salts based on the 5-(4-(alkyloxy)phenyl)-1,2,4-triazol-4-ium cation bearing a perfluoroalkyl chain with triflate, tetrafluoroborate and bistriflimide anion are reported. The cations are regarded as triphilic on account of their three distinct regions – hydrocarbon, fluorocarbon and ionic. The mesophases were characterised by a combination of polarised optical microscopy, calorimetry and small-angle scattering experiments using both X-rays and neutrons, while thermal stability was probed using thermogravimetric analysis. The liquid crystal properties are found to be dependent on the anion and the length of …

Thermogravimetric analysis3104TetrafluoroborateMaterials science3107Impedance spectroscopyIonic bonding02 engineering and technology010402 general chemistry01 natural sciencesSettore CHIM/12 - Chimica Dell'Ambiente E Dei Beni Culturalichemistry.chemical_compoundLiquid crystalMaterials ChemistryThermal stabilityBistriflimidePhysical and Theoretical Chemistry16071606SpectroscopySANSSAXSSettore CHIM/06 - Chimica Organica021001 nanoscience & nanotechnologyCondensed Matter PhysicsAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic MaterialsCrystallographyTriphilicchemistryIonic liquid25052504Ionic liquid crystal0210 nano-technologyTrifluoromethanesulfonateJournal of Molecular Liquids
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Carbon Nano-onions: Potassium Intercalation and Reductive Covalent Functionalization

2021

Herein we report the synthesis of covalently functionalized carbon nano-onions (CNOs) via a reductive approach using unprecedented alkali-metal CNO intercalation compounds. For the first time, an in situ Raman study of the controlled intercalation process with potassium has been carried out revealing a Fano resonance in highly doped CNOs. The intercalation was further confirmed by electron energy loss spectroscopy and X-ray diffraction. Moreover, the experimental results have been rationalized with DFT calculations. Covalently functionalized CNO derivatives were synthesized by using phenyl iodide and n-hexyl iodide as electrophiles in model nucleophilic substitution reactions. The functiona…

Thermogravimetric analysisIodideIntercalation (chemistry)02 engineering and technology010402 general chemistryPhotochemistry01 natural sciences7. Clean energyBiochemistryArticleCatalysissymbols.namesakeColloid and Surface ChemistryNucleophilic substitutionchemistry.chemical_classificationElectron energy loss spectroscopytechnology industry and agricultureGeneral Chemistry021001 nanoscience & nanotechnologyEspectroscòpia Raman0104 chemical scienceschemistryCovalent bondsymbolsSurface modificationMaterials nanoestructurats0210 nano-technologyRaman spectroscopyJournal of the American Chemical Society
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Characterization of Hydrophilic Gold(I) N-Heterocyclic Carbene (NHC) Complexes as Potent TrxR Inhibitors Using Biochemical and Mass Spectrometric App…

2017

We report here on the synthesis of a series of mono-and dinuclear gold(I) complexes exhibiting sulfonated bis(NHC) ligands and novel hydroxylated mono(NHC) Au(I) compounds, which were also examined for their 'biological activities. Initial cell viability assays show strong antiproliferative activities of the hydroxylated mono(NHC) gold compounds (8 > 9 > 10) against 2008 human ovarian cancer cells even after 1 h incubation. In order to gain insight into the mechanism of biological action of the gold compounds, their effect on the pivotal cellular target seleno-enzyme thioredoxin reductase (TrxR), involved in the maintenance of intracellular redox balance, was investigated in depth. Th…

Thioredoxin Reductase 1AuranofinSilverStereochemistryThioredoxin reductaseThioredoxin Reductase 2WATER-SOLUBLE RUTHENIUM(II)Antineoplastic Agents010402 general chemistryG-quadruplexLigandsIN-VITRO CYTOTOXICITYLIGANDS SYNTHESIS01 natural sciencesInorganic Chemistrychemistry.chemical_compoundDrug StabilityThioredoxin Reductase 1Coordination ComplexesTHIOREDOXIN REDUCTASE INHIBITIONCell Line TumormedicineOrganogold CompoundsAnimalsHumansCRYSTAL-STRUCTURESPhysical and Theoretical ChemistryCANCER CELLSBIOLOGICAL-PROPERTIES010405 organic chemistryChemistryMOLECULAR-MECHANISMSDNA0104 chemical sciencesRatsG-QuadruplexesGlutathione ReductaseSolubilityBiological targetCancer cellPLATINUM ANTICANCER DRUGSMETAL-COMPLEXESGoldReactive Oxygen SpeciesCarbeneHydrophobic and Hydrophilic InteractionsOrganogold Compoundsmedicine.drugInorganic Chemistry
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PHEA-graft-polybutylmethacrylate copolymer microparticles for delivery of hydrophobic drugs.

2012

Abstract Polymeric microparticles encapsulating two model hydrophobic drugs, beclomethasone dipropionate (BDP) and flutamide (FLU) were prepared by using the high pressure homogenization-solvent evaporation method starting from a oil-in-water emulsion. For the preparation of polymeric microparticles a α,β-poly(N-2-hydroxyethyl)- d , l -aspartamide (PHEA) graft copolymer with comb like structure was properly synthesized via grafting from atom transfer radical polymerization (ATRP) technique, by using two subsequent synthetic steps. In the first step a polymeric multifunctional macroinitiator was obtained by the conjugation of a proper number of 2-bromoisobutyryl bromide (BIB) residues to the…

Time FactorsBioadhesivePharmaceutical ScienceCell LineDrug Delivery SystemsPolymethacrylic AcidsPolymer chemistryMucoadhesionCopolymerSide chainHumansPhea polybutylmethacrylate microparticles drug deliveryParticle SizeGlucocorticoidsDrug CarriersDose-Response Relationship DrugChemistryAtom-transfer radical-polymerizationBeclomethasoneAdhesivenessAndrogen AntagonistsGraftingFlutamideMicrospheresPolymerizationDelayed-Action PreparationsEmulsionSolventsNanoparticlesEmulsionsCaco-2 CellsPeptidesHydrophobic and Hydrophilic InteractionsInternational journal of pharmaceutics
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Effects of hydrazyl group containing drugs on leucocyte functions: an immunoregulatory model for the hydralazine-induced lupus-like syndrome.

1985

Isoniazid (INH) and hydralazine (HYD) are transglutaminase (TGase, E.C.2.3.2.13.) substrates containing catalytically recruitable hydrazyl groups. Since they can be expected to inhibit TGase-mediated cell functions by competing with physiological substrates, their effect upon allogeneically and lectin-induced proliferation of mononucleocytes and upon zymosan-induced chemiluminescence of phagocytes was studied. Both compounds inhibited chemiluminescence in a dose-dependent manner. ID50 of HYD was consistently below 20 microM, while that of INH was above 120 microM. Proliferation of immunocompetent cells was suppressed by HYD with an ID50 of 60 microM, INH was inhibitory only above 5000 micro…

Tissue transglutaminaseImmunologyIn Vitro TechniquesToxicologyLymphocyte ActivationModels BiologicalIn vivomedicineConcanavalin AIsoniazidLeukocytesHumansLupus Erythematosus SystemicPharmacologychemistry.chemical_classificationTransglutaminasesbiologySyndromeHydralazineHydralazineEnzymeMechanism of actionchemistryBiochemistryConcanavalin AToxicityLipophilicityLuminescent Measurementsbiology.proteinmedicine.symptommedicine.drugJournal of immunopharmacology
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