Search results for "Nanoparticles"
showing 10 items of 1286 documents
Selective chromo-fluorogenic detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) with a unique probe based on a boron dipyrromethene …
2014
[EN] A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with…
Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation
2012
Marine biofouling—the colonization of small marine microorganisms on surfaces that are directly exposed to seawater, such as ships' hulls—is an expensive problem that is currently without an environmentally compatible solution1. Biofouling leads to increased hydrodynamic drag, which, in turn, causes increased fuel consumption and greenhouse gas emissions. Tributyltin-free antifouling coatings and paints1, 2, 3, 4 based on metal complexes or biocides have been shown to efficiently prevent marine biofouling. However, these materials can damage5 the environment through metal leaching (for example, of copper and zinc)6 and bacteria resistance7. Here, we show that vanadium pentoxide nanowires ac…
Macrophage-Specific Lipid-Based Nanoparticles Improve Cardiac Magnetic Resonance Detection and Characterization of Human Atherosclerosis
2009
ObjectivesWe sought to determine whether gadolinium (Gd)-containing lipid-based nanoparticles (NPs) targeting the macrophage scavenger receptor-B (CD36) improve cardiac magnetic resonance (CMR) detection and characterization of human atherosclerosis.BackgroundGd-containing lipid-based NPs targeting macrophages have improved MR detection of murine atherosclerosis.MethodsGadolinium-containing untargeted NPs, anti-CD36 NPs, and nonspecific Fc-NPs were created. Macrophages were incubated with fluorescent targeted and nontargeted NPs to determine uptake via confocal microscopy and inductively coupled plasma mass spectroscopy (ICP-MS) quantified Gd uptake. Human aortic specimens were harvested at…
A trifunctional dextran-based nanovaccine targets and activates murine dendritic cells, and induces potent cellular and humoral immune responses in v…
2013
Dendritic cells (DCs) constitute an attractive target for specific delivery of nanovaccines for immunotherapeutic applications. Here we tested nano-sized dextran (DEX) particles to serve as a DC-addressing nanocarrier platform. Non-functionalized DEX particles had no immunomodulatory effect on bone marrow (BM)-derived murine DCs in vitro. However, when adsorbed with ovalbumine (OVA), DEX particles were efficiently engulfed by BM-DCs in a mannose receptor-dependent manner. A DEX-based nanovaccine containing OVA and lipopolysaccharide (LPS) as a DC stimulus induced strong OVA peptide-specific CD4(+) and CD8(+) T cell proliferation both in vitro and upon systemic application in mice, as well a…
Preservation of dendritic cell function upon labeling with amino functionalized polymeric nanoparticles.
2010
Dendritic cells (DCs) are key players in eliciting immunity against antigens, therefore making them the focus of many investigations on immune responses in infections, cancer and autoimmune diseases. Nanosized materials have just recently been investigated for their use as carriers of antigens and as labeling agents for DCs. For this later use nanoparticles should be non-toxic and should most importantly not alter the physiological functions of DCs. Here we demonstrate that by the use of polymeric fluorescent nanoparticles as synthesized by the miniemulsion process immature DCs (iDCs) can be efficiently labeled intracellularly. Amino functionalized nanoparticles are more effective than carb…
Functionalized Polystyrene Nanoparticles Trigger Human Dendritic Cell Maturation Resulting in Enhanced CD4+T Cell Activation
2012
Nanoparticles (NP) represent a promising tool for biomedical applications. Here, sulfonate- and phosphonate-functionalized polystyrene NP are analyzed for their interaction with human monocyte-derived dendritic cells (DC). Immature dendritic cells (iDC) display a higher time- and dose-dependent uptake of functionalized polystyrene NP compared to mature dendritic cells (mDC). Notably, NP induce an enhanced maturation of iDC but not of mDC (upregulation of stimulatory molecules and cytokines). NP-triggered maturation results in a significantly enhanced T cell stimulatory capacity (increased CD4(+) T cell proliferation and IFN-γ production), indicating a shift to a pronounced Th1 response. Imm…
PLGA Nanoparticles Co-encapsulating NY-ESO-1 Peptides and IMM60 Induce Robust CD8 and CD4 T Cell and B Cell Responses
2021
Contains fulltext : 232076.pdf (Publisher’s version ) (Open Access) Tumor-specific neoantigens can be highly immunogenic, but their identification for each patient and the production of personalized cancer vaccines can be time-consuming and prohibitively expensive. In contrast, tumor-associated antigens are widely expressed and suitable as an off the shelf immunotherapy. Here, we developed a PLGA-based nanoparticle vaccine that contains both the immunogenic cancer germline antigen NY-ESO-1 and an α-GalCer analog IMM60, as a novel iNKT cell agonist and dendritic cell transactivator. Three peptide sequences (85-111, 117-143, and 157-165) derived from immunodominant regions of NY-ESO-1 were se…
Nanoparticles and antigen-specific T-cell therapeutics: A comprehensive study on uptake and release
2015
Aim: T lymphocytes are used as cellular therapeutics in many disease entities including cancer. We investigated the uptake and retention of nanoparticles (NPs) by these nonphagocytic cells. Materials & methods: Uptake, release and toxicity of various polymeric NP preparations were analyzed by flow cytometry, confocal laser scanning microscopy and transmission electron microscopy. T-cell effector functions were measured using IFN-γ-ELISPOT and 51Chromium-release assays. Results: Amino-functionalized NPs were efficiently ingested by antigen-specific T cells without adversely influencing effector functions. NPs were stored in membrane-surrounded vesicles, with major proportions released e…
A multifuctional nanoplatform for drug targeted delivery based on radiation-engineered nanogels
2020
Abstract Under a rational design, combining biologically active molecules, ligands to specific cell receptors and fluorescent, radioactive or paramagnetic labels into a single nano-object can bridge the unique properties of the individual components and improve conventional sensing, imaging and therapeutic efficacies. The validation of these functional nano-objects requires careful testing both in terms of physico-chemical properties and biological behaviour in vitro and in vivo, prior to translation into the clinic. Ionising radiation of aqueous polymer solutions is a viable strategy to produce multifunctional nanogels from aqueous solutions of hydrophilic polymers. By proper selection of …
CFD simulation of ZnO nanoparticle precipitation in a supercritical water synthesis reactor
2012
International audience; Continuous hydrothermal flow synthesis process has shown great advantages concerning the control of particle size and morphology through the optimization of supercritical water processing parameters. In particular, micromixing is a key issue of the process for controlling the nucleation mechanism. A Computational Fluid Dynamics (CFD) model is suggested for nanoparticle size determination using a population balance approach. Models for reaction kinetics, thermodynamics, nucleation and growth are presented. The effects of base concentration and hydrodynamics are investigated. Results show that the CFD may be valuable simulation tool for controlling the size and the sha…