Search results for " Hydrophilic"

showing 10 items of 236 documents

The introduction of fluorine atoms or trifluoromethyl groups in short cationic peptides enhances their antimicrobial activity

2006

The effect of introducing fluorine atoms or trifluoromethyl groups in either the peptidic chain or the C-terminal end of cationic pentapeptides is reported. Three series of amide and ester peptides were synthesised and their antimicrobial properties evaluated. An enhanced activity was found in those derivatives whose structure contained fluorine, suggesting an increase in their hydrophobicity.

StereochemistryClinical BiochemistryPharmaceutical Sciencechemistry.chemical_elementPeptideMicrobial Sensitivity TestsBiochemistryChemical synthesisMedicinal chemistryStructure-Activity Relationshipchemistry.chemical_compoundCationsAmideBenzyl CompoundsDrug DiscoveryHumansMolecular Biologychemistry.chemical_classificationTrifluoromethylMolecular StructureOrganic ChemistryCationic polymerizationStereoisomerismBiological activityFluorineAnti-Bacterial AgentsEukaryotic CellschemistryDrug DesignLipophilicityFluorineMolecular MedicineHydrophobic and Hydrophilic InteractionsOligopeptidesBioorganic & Medicinal Chemistry
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Mononuclear rearrangement of heterocycles in zwitterionic micelles of amine oxide surfactants.

2012

Abstract Rate constants for the mononuclear rearrangement (MRH) of Z -phenylhydrazones of some 5-substituted-3-benzoyl-1,2,4-oxadiazoles in water have been measured in the presence of zwitterionic micelles. The use of micellized N -tetradecyl- N , N -dimethylamineoxide (C 14 DMAO) as the reaction medium allowed to solubilize the otherwise water-insoluble oxadiazoles. Micellar rate effects were analyzed by using a simple pseudo-phase model and compared with those obtained in non-ionic micelles (Triton X-100). Evidence that both the rate of the rearrangement reaction and the binding of the substrates to the micelles are mainly governed by substrate hydrophobicity is obtained. The disagreement…

Steric effectsSpectrometry Mass Electrospray IonizationN-tetradecyl-NOctoxynolPhotochemistryMicelleMononuclear rearrangements of heterocycles (MHRs)Biomaterialschemistry.chemical_compoundSurface-Active AgentsColloid and Surface ChemistryReaction rate constantMicellar catalysiN-tetradecyl-NN-dimethylamineoxidePolymer chemistryRearrangement reactionzwitterionic micelleMicellesOxadiazolesHydrazonesSubstrate (chemistry)WaterSettore CHIM/06 - Chimica OrganicaSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsAmine oxideKineticschemistrySolubilitySolubilizationN-dimethylamineoxideThermodynamicsHydrophobic and Hydrophilic InteractionsMyristic AcidsDimethylaminesJournal of colloid and interface science
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Acid- and Base-Catalysis in the Mononuclear Rearrangement of Some (Z)-arylhydrazones of 5-Amino-3-benzoyl-1,2,4-oxadiazole in Toluene: Effect of Subs…

2011

The reaction rates for the rearrangement of eleven (Z)-arylhydrazones of 5-amino-3-benzoyl-1,2,4-oxadiazole 3a-k into the relevant (2-aryl-5-phenyl-2H-1, 2,3-triazol-4-yl)ureas 4a-k in the presence of trichloroacetic acid or of piperidine have been determined in toluene at 313.1 K. The results have been related to the effect of the aryl substituent by using Hammett and/or Ingold-Yukawa-Tsuno correlations and have been compared with those previously collected in a protic polar solvent (dioxane/water) as well as with those on the analogous rearrangement of the corresponding (Z)-arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole 1a-k in benzene. Some light can thus be shed on the general di…

SubstituentOxadiazoleAlkaliesMedicinal chemistryCatalysisDioxanesStructure-Activity RelationshipAcid catalysischemistry.chemical_compoundPiperidinesUreaOrganic chemistryAminesTrichloroacetic AcidBenzeneBiological ProductsOxadiazolesMolecular StructureArylMRH acid- and base-catalysis kinetic measurementsOrganic ChemistryHydrazonesTemperatureWaterSettore CHIM/06 - Chimica OrganicaTolueneSolventKineticschemistryMononuclear rearrangements of heterocycles; (Z)-Arylhydrazones; acid catalysis; base catalysis.PiperidineHydrophobic and Hydrophilic InteractionsToluene
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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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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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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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Synthesis of Mesoporous Supraparticles on Superamphiphobic Surfaces

2015

A method for mesoporous supraparticle synthesis on superamphiphobic surfaces is designed. Therefore, supraparticles assembled with nanoparticles are synthesized by the evaporation of nanoparticle dispersion drops on the superamphiphobic surface. For synthesis, no further purification is required and no organic solvents are wasted. Moreover, by changing the conditions such as drop size and concentration, supraparticles of different sizes, compositions, and architectures are fabricated.

TitaniumMaterials scienceDrop sizeSurface PropertiesMechanical EngineeringMetal NanoparticlesTin CompoundsWaterNanoparticlechemistry.chemical_elementNanoparticle dispersionEvaporation (deposition)Chemical engineeringchemistryMechanics of MaterialsMicroscopy Electron ScanningGeneral Materials SciencePorosityMesoporous materialMetal nanoparticlesHydrophobic and Hydrophilic InteractionsPorosityTitanium
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Refractive index and equilibrium water content of conventional and silicone hydrogel contact lenses

2006

Prova tipográfica (In Press)

Traditional handheld refractometerMaterials scienceSiliconesRefractive index02 engineering and technologyRefraction Ocular03 medical and health scienceschemistry.chemical_compound0302 clinical medicineOpticsSiliconeRefractometerHumanssilicone hydrogelCLR 12-70Siloxane hydrogelScience & TechnologyEquilibrium water contentbusiness.industryWaterHydrogelsHEMAEquipment DesignContact Lenses Hydrophilic021001 nanoscience & nanotechnologyAtago N-2ESensory SystemsContact lensOphthalmologyRefractometrysoft contact lenschemistrySiloxaneSelf-healing hydrogels030221 ophthalmology & optometry0210 nano-technologybusinessRefractive indexRefractometryconventional hydrogelOptometryBiomedical engineering
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