Search results for "Silica nanoparticles"

showing 10 items of 50 documents

2D dynamical arrest transition in a mixed nanoparticle-phospholipid layer studied in real and momentum spaces

2015

AbstractWe investigate the interfacial dynamics of a 2D self-organized mixed layer made of silica nanoparticles interacting with phospholipid (DPPC) monolayers at the air/water interface. This system has biological relevance, allowing investigation of toxicological effects of nanoparticles on model membranes and lung surfactants. It might also provide bio-inspired technological solutions, exploiting the self-organization of DPPC to produce a non-trivial 2D structuration of nanoparticles. The characterization of interfacial dynamics yields information on the effects of NPs on the mechanical properties, important to improve performances of systems such as colloidosomes, foams, creams. For thi…

Surface PropertiesComputer sciencePhospholipidNanoparticleRELAXATIONCOLLOIDOSOMESRespiratory physiologySurface pressureArticleMomentumchemistry.chemical_compoundPhase (matter)MonolayerParticle SizeSILICA NANOPARTICLESPhospholipidsBrownian motionSimulation[PHYS]Physics [physics]MultidisciplinaryAirRelaxation (NMR)WaterPulmonary SurfactantsModels TheoreticalSilicon DioxideSURFACTANTCharacterization (materials science)MembranechemistryChemical physicsNanoparticlesWater chemistryParticle sizeCOLLOIDAL GLASS-TRANSITIONAlgorithmsScientific Reports
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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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Interactions of silica nanoparticles with lung epithelial cells and the association to flotillins

2012

Amorphous silica nanoparticles (aSNPs) gain increasing popularity for industrial and therapeutic claims. The lung with its surface area of 100-140 m(2) displays an ideal target for therapeutic approaches, but it represents also a serious area of attack for harmful nanomaterials. The exact nature of the cytotoxic effects of NPs is still unknown. Furthermore, cellular pathways and the destiny of internalized NPs are still poorly understood. Therefore, we examined the cytotoxicity (MTS, LDH) and inflammatory responses (IL-8) for different-sized aSNPs (30, 70, 300 nm) on our lung epithelial cells line NCI H441 and endothelial cell line ISO-HAS-1. Additionally, colocalization studies have been c…

Time FactorsEndosomeCell SurvivalHealth Toxicology and MutagenesisEndothelial cellsCytotoxicityEndosomessilica nanoparticlesToxicologyEndocytosisTransfectionClathrinFlotillin-1siliciumFlotillin-2Alveolar-capillary barrierCell Line TumorAlveolar capillary barrierHumansInterleukin 8Inorganic CompoundsParticle SizeCytotoxicityLungbiologyDose-Response Relationship DrugL-Lactate DehydrogenaseInterleukin-8Membrane ProteinsInflammatory responseEpithelial CellsGeneral MedicineTransfectionSilicon DioxideEndocytosisCell biologyLung epithelial cellsEndothelial stem cellEndocytic vesiclebiology.proteinNanoparticlesRNA InterferenceInflammation Mediators
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Determination of the LD50 with the chick embryo chorioallantoic membrane (CAM) assay as a promising alternative in nanotoxicological evaluation

2021

Toxicity tests in rodents are still considered a controversial topic concerning their ethical justifiability. The chick embryo chorioallantoic membrane (CAM) assay may offer a simple and inexpensive alternative. The CAM assay is easy to perform and has low bureaucratic hurdles. At the same time, the CAM assay allows the application of a broad variety of analytical methods in the field of nanotoxicological research. We evaluated the CAM assay as a methodology for the determination of nanotoxicity. Therefore we calculated the median lethal dose (LD50), performed in vivo microscopy and immunohistochemistry to identify organ-specific accumulation profiles, potential organ damage, and the kineti…

animal structuresChemistryeducationBiomedical EngineeringEmbryo02 engineering and technology010501 environmental sciences021001 nanoscience & nanotechnologyToxicology01 natural sciencesCell biologySilica nanoparticlesChorioallantoic membraneNanotoxicologyembryonic structures0210 nano-technologyCam assay0105 earth and related environmental sciences
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Chromogenic Detection of Aqueous Formaldehyde Using Functionalized Silica Nanoparticles

2016

Silica nanoparticles functionalized with thiol reactive units and bulky polar polyamines were used for the selective colorimetric detection of formaldehyde. The reaction of thiols groups in the nanoparticles surface with a squaraine dye resulted in loss of the pi-conjugation of the chromophores, and the subsequent bleaching of the solution. However, when formaldehyde was present in the suspension, the thiol-squaraine reaction was inhibited and a chromogenic response was observed. A selective response to formaldehyde was observed only when the thiol and polyamine groups were anchored to the silica surface. The observed selective response was ascribed to the fact that bulky polyamines generat…

aqueous detectionFormaldehydeNanoparticle02 engineering and technologysilica nanoparticles010402 general chemistryPhotochemistry01 natural scienceschemistry.chemical_compoundQUIMICA ORGANICAhybrid materialsGeneral Materials SciencesensingDetection limitchemistry.chemical_classificationSquaraine dyeAqueous solutionChromogenicQUIMICA INORGANICA021001 nanoscience & nanotechnology0104 chemical scienceschemistryThiolformaldehyde0210 nano-technologyHybrid material
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Fluorescein- and EGFR-Antibody Conjugated Silica Nanoparticles for Enhancement of Real-time Tumor Border Definition Using Confocal Laser Endomicrosco…

2019

Intraoperative definition of tumor free resection margins in head and neck cancer is challenging. In the current proof-of-principle study we evaluated a novel silica nanoparticle-based agent for its potential use as contrast enhancer. We synthesized silica nanoparticles with an average size of 45 nm and modified these particles with the fluorescence stain fluorescein isocyanate (FITC) for particle detection and with epidermal growth factor receptor (EGFR)-targeting antibodies for enhanced tumor specificity. The nanoparticles exhibited good biocompatibility and could be detected in vitro and in vivo by confocal laser scanning microscopy. Additionally, we show in an ex vivo setting that these…

biologyBiocompatibilityGeneral Chemical EngineeringConfocalEGFRcontrast agentsilica nanoparticlesStainEGFR AntibodyArticlelcsh:Chemistry03 medical and health scienceschemistry.chemical_compound0302 clinical medicinechemistrylcsh:QD1-999In vivo030220 oncology & carcinogenesisbiology.proteinGeneral Materials ScienceEpidermal growth factor receptorFluorescein030223 otorhinolaryngologyEx vivoBiomedical engineeringNanomaterials
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MODIFICA SUPERFICIALE DI FILM DI POLY(ETILENE-co-ACIDO ACRILICO) CON NANOPARTICELLE DI SILICE ATTIVATA

2009

chemical surface modification hybrid materialsgrafting from grafting to silica nanoparticles
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2020

Biomolecules, and particularly proteins, bind on nanoparticle (NP) surfaces to form the so-called protein corona. It is accepted that the corona drives the biological distribution and toxicity of NPs. Here, the corona composition and structure were studied using silica nanoparticles (SiNPs) of different sizes interacting with soluble yeast protein extracts. Adsorption isotherms showed that the amount of adsorbed proteins varied greatly upon NP size with large NPs having more adsorbed proteins per surface unit. The protein corona composition was studied using a large-scale label-free proteomic approach, combined with statistical and regression analyses. Most of the proteins adsorbed on the N…

chemistry.chemical_classificationendocrine systemGeneral Chemical EngineeringBiomoleculeNanoparticleProtein Corona02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnologyElectrostatics01 natural sciencesYeast0104 chemical sciencesSilica nanoparticlesAdsorptionchemistryChemical engineeringGeneral Materials ScienceComposition (visual arts)0210 nano-technologyNanomaterials
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Protein recovery as a resource from waste specifically via membrane technology : from waste to wonder

2021

Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein re…

potato processing wastemembrane foulingmicroalgaejätevesikalvotekniikka (erotusmenetelmät)talteenottopurple phototrophic bacteriaelintarviketeollisuusbiomassa (teollisuus)mikrobitproteiinitmesoporous silica nanoparticlesadsorptioalfalfa processing wastedairy waste proteinwastewaters
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Luminescence properties induced by sintering of silica nanoparticles

2014

The effect of sintering on the optical properties of silica nanoparticles, a mean diameter of ~14 nm, are investigated by absorption and luminescence experiments. The sintering is induced by a thermal treatment of 1000 °C for 272 hours; after that the sample is transparent, and emits a bright luminescence under UV excitation. Time resolved photoluminescence spectra excited by a tunable laser source allows to evidence four bands around 2.0 eV, 2.4 eV, 2.7 eV and 3.4 eV, peculiar to defects induced by the sintering.

silica nanoparticles sintering time-resolved luminescence
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