Search results for "Nanoparticles"
showing 10 items of 1286 documents
Cloud point–dispersive μ-solid phase extraction of hydrophobic organic compounds onto highly hydrophobic core–shell Fe 2 O 3 @C magnetic nanoparticles
2012
Abstract A novel two-step extraction technique combining cloud point extraction (CPE) with dispersive micro-solid phase extraction (D-μ-SPE) is presented in this work for the first time. The method involves initial extraction of the target analytes by CPE in the micelles of a non-ionic surfactant medium; then highly hydrophobic polysiloxane-coated core–shell Fe 2 O 3 @C magnetic nanoparticles (MNPs) are used to retrieve the micellar phase. In that manner, the micellar phase containing the analytes is the target of the D-μ-SPE step rather than the analytes directly. MNPs are then collected by the application of an adscititious magnetic field overcoming the need for specific steps associated …
Visible-ultraviolet vibronic emission of silica nanoparticles
2014
We report the study of the visible-ultraviolet emission properties and the structural features of silica nanoparticles prepared through a laboratory sol-gel technique. Atomic force microscopy, Raman and Infrared investigations highlighted the 10 nm size, purity and porosity of the obtained nanoparticles. By using time resolved photoluminescence techniques in air and in a vacuum we were able to single out two contributions in the visible emission: the first, stable in both atmospheres, is a typical fast blue band centered around 2.8 eV; the second, only observed in a vacuum around the 3.0-3.5 eV range, is a vibrational progression with two phonon modes at 1370 cm(-1) and 360 cm(-1). By fully…
Cytotoxicity of Metal and Semiconductor Nanoparticles Indicated by Cellular Micromotility
2009
In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are required to achieve a detailed knowledge of toxicity and biodegradation as a function of the nanoparticles' physical and chemical properties. In this study, we show that the micromotility of animal cells as monitored by electrical cell-substrate impedance analysis (ECIS) is highly suitable to quantify in vitro cytotoxicity of semiconductor quantum dots and gold nanorods…
Release of copper-amended particles from micronized copper-pressure-treated wood during mechanical abrasion
2016
Background We investigated the particles released due to abrasion of wood surfaces pressure-treated with micronized copper azole (MCA) wood preservative and we gathered preliminary data on its in vitro cytotoxicity for lung cells. The data were compared with particles released after abrasion of untreated, water (0% MCA)-pressure-treated, chromated copper (CC)-pressure-treated wood, and varnished wood. Size, morphology, and composition of the released particles were analyzed. Results Our results indicate that the abrasion of MCA-pressure-treated wood does not cause an additional release of nanoparticles from the unreacted copper (Cu) carbonate nanoparticles from of the MCA formulation. Howev…
Junction Effect on the Photocatalytic Activity of Mixed-Phase TiO2 Nanoparticles
2010
Active TiO2 photocatalysts were prepared under mild experimental conditions by thermohydrolysis of TiCl4 in pure water at 100 {degree sign}C. The preparation method is very simple and does not require the use of expensive thermal or hydrothermal treatments. Depending on the TiCl4/H2O ratio, pure rutile, binary mixtures of anatase and rutile or anatase and brookite, or ternary mixtures of anatase, brookite and rutile, can be obtained. 4-nitrophenol photodegradation was used to evaluate the photoactivity of the various powders. The high photocatalytic activity of the mixed samples was explained by the presence of junctions among different polymorphic TiO2 phases that allows an improved charge…
Drift of ferrocolloids through a cylindrical grid by magnetic force
2011
The subject of the paper is to investigate the coupling phenomena of magnetic and non-uniform temperature fields in ferrofluids. The coupling creates a special kind of mass transfer and an inhomogeneous concentration of ferrofluid arises especially near bodies, where higher field gradients are present. Particular attention is paid to the oriented mass transfer, i.e. the magnitude and direction of ferrofluid flux with respect to the temperature gradient and magnetic field. Quantitatively, oriented phoretic transport can be characterized by the magnetic Soret coefficient and osmotic pressure difference. The problem is solved using two-dimensional (2D) numerical simulations for the periodic st…
Usage of moving nanoparticles for improved holographic recording
2013
Metal nanoparticles are used for different applications in holographic configurations. The metal nanoparticles are placed close to an object and encode it by a time varying random mask. A decoding mask is computed and used to obtain super-resolution digital hologram and eliminate the twin image and DC from a digital hologram. The method is also shown to be applicable for other optical methods.
SOLID LIPID NANOPARTICLES FOR APPLICATIONS IN GENE THERAPY: A REVIEW OF THE STATE OF THE ART
2010
Importance of the field. Gene therapy represents a new paradigm in the prevention and treatment of many inherited and acquired diseases, including genetic disorders, such as cystic fibrosis, haemophilia and many somatic diseases, such as tumours, neurodegenerative diseases and viral infections, such as AIDS. Areas covered in this review. Among a large array of non-viral transfection agents used for in-vitro applications, cationic SLNs are the topic of this review, being recently proposed as an alternative carrier for DNA delivery, due to many technological advantages such as large-scale production from substances generally recognized as safe, good storage stability and possibility of steam …
Low density lipoproteins and human serum albumin as the carriers of squalenoylated drugs: insights from molecular simulations
2018
We have studied the interaction of three clinically promising squalenoylated drugs (gemcitabine-squalene, adenine-squalene, and doxorubicin-squalene) with low-density lipoproteins (LDL) by means of atomistic molecular dynamics simulations. It is shown that all studied squalenoylated drugs accumulate inside the LDL particles. This effect is promoted by the squalene moiety, which acts as an anchor and drives the hydrophilic drugs into the hydrophobic core of the LDL lipid droplet. Our data suggest that LDL particles could be a universal carriers of squalenoylated drugs in the bloodstream. Interaction of gemcitabine-squalene with human serum albumin (HSA) was also studied by ensemble of dockin…
Exploiting the Opportunity to Use Plant-Derived Nanoparticles as Delivery Vehicles
2023
The scientific community has become increasingly interested in plant-derived nanoparticles (PDNPs) over the past ten years. Given that they possess all the benefits of a drug carrier, including non-toxicity, low immunogenicity, and a lipid bilayer that protects its content, PDNPs are a viable model for the design of innovative delivery systems. In this review, a summary of the prerequisites for mammalian extracellular vesicles to serve as delivery vehicles will be given. After that, we will concentrate on providing a thorough overview of the studies investigating the interactions of plant-derived nanoparticles with mammalian systems as well as the loading strategies for encapsulating therap…