Search results for " NANOPARTICLES"
showing 10 items of 794 documents
Catechol-Initiated Polyethers: Multifunctional Hydrophilic Ligands for PEGylation and Functionalization of Metal Oxide Nanoparticles
2012
Bifunctional CA-PEG (catechol-poly(ethylene glycol)) and multifunctional CA-PEG-PGA/PEVGE (poly(glycidyl amine)/poly(ethylene glycol vinyl glycidyl ether)) ligands for the functionalization and solubilization of nanoparticles are introduced. Tunable polymers with polydispersities1.25 and molecular weights in the range 500-7700 g mol(-1) containing a catechol moiety for conjugation to metal oxide nanoparticles were prepared. The functional PEG ligands were synthesized starting from the acetonide-protected catechol initiator 2,2-dimethyl-1,3-benzodioxole-5-propanol (CA-OH) for oxyanionic polymerization. CA-OH was used both for homopolymerization of ethylene oxide (EO) as well as copolymerizat…
Novel cationic solid-lipid nanoparticles as non-viral vectors for gene delivery.
2007
In this paper, the suitability of novel cationic solid-lipid nanoparticles (SLN) as a nonviral transfection agent for gene delivery was investigated. SLN were produced by using the microemulsion method and Compritol ATO 888 as matrix lipid, dimethyldioctadecylammonium bromide as charge carrier and Pluronic F68 as surfactant. Obtained nanoparticles were approximately 120 nm in size and positively charged, with a zeta potential value equal to +45 mV in twice-distilled water. Cationic SLN were able to form stable complexes with DNA and to protect DNA against DNase I digestion. The SLN-DNA complexes were characterized by mean diameter and zeta potential measurements. In vitro studies on human l…
Use of the Cultex® Radial Flow System as an in vitro exposure method to assess acute pulmonary toxicity of fine dusts and nanoparticles with special …
2013
Exposure of the respiratory tract to airborne particles (including metal-dusts and nano-particles) is considered as a serious health hazard. For a wide range of substances basic knowledge about the toxic properties and the underlying pathomechanisms is lacking or even completely missing. Legislation demands the toxicological characterization of all chemicals placed on the market until 2018 (REACH). As toxicological in vivo data are rare with regard to acute lung toxicity or exhibit distinct limitations (e.g. inter-species differences) and legislation claims the reduction of animal experiments in general ("3R" principle), profound in vitro models have to be established and characterized to m…
Inulin-Ethylenediamine Coated SPIONs Magnetoplexes: A Promising Tool for Improving siRNA Delivery.
2015
An inulin based polycation (Inu-EDA) has been synthesized by the grafting of ethylenediamine molecules onto inulin backbone. The obtained inulin copolymer has been though to coat SPIONs (IC-SPIONs) and obtain stable magnetoplexes by complexation of IC-SPIONs with a model duplexed siRNA, for improving oligonucleotide transfection efficiency.The physical-chemical characteristics of IC-SPIONs and IC-SPIONs/siRNA magnetoplexes have been investigated by scanning and transmission electron microscopies, dynamic light scattering, FT-IR and qualitative surface elementary analysis. Cell compatibility and internalization in vitro of IC-SPIONs have been evaluated by MTS and fluorescence microscopy resp…
Synthesis, spectroscopic studies and biological evaluation of acridine derivatives: The role of aggregation on the photodynamic efficiency.
2018
Two new photoactive compounds (1 and 2) derived from the 9-amidoacridine chromophore have been synthesized and fully characterized. Their abilities to produce singlet oxygen upon irradiation have been compared. The synthesized compounds show very different self-aggregating properties since only 1 present a strong tendency to aggregate in water. Biological assays were conducted with two cell types: hepatoma cells (Hep3B) and human umbilical vein endothelial cells (HUVEC). Photodynamic therapy (PDT) studies carried out with Hep3B cells showed that non-aggregating compound 2 showed photoxicity, ascribed to the production of singlet oxygen, being aggregating compound 1 photochemically inactive.…
Novel Lipid and Polymeric Materials as Delivery Systems for Nucleic Acid Based Drugs
2015
Nucleic acid based drugs (NADBs) are short DNA/RNA molecules that include among others, antisense oligonucleotides, aptamers, small interfering RNAs and micro-interfering RNAs. Despite the different mechanisms of actions, NABDs have the ability to combat the effects of pathological gene expression in many experimental systems. Thus, nowadays, NABDs are considered to have a great therapeutic potential, possibly superior to that of available drugs. Unfortunately, however, the lack of effective delivery systems limits the practical use of NABDs. Due to their hydrophilic nature, NABDs cannot efficiently cross cellular membrane; in addition, they are subjected to fast degradation by cellular and…
Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids.
2021
Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in…
ChemInform Abstract: Solution Synthesis of Nanoparticular Binary Transition Metal Antimonides.
2011
The transition metal antimonides MSb with M: Co, Ni, and Zn and Cu2Sb with particle sizes ranging from 20 to 60 nm are prepared using presynthesized antimony nanoparticles and activated metal nanoparticles as precursors.
Mesoporous Silica Nanoparticles in Chemical Detection: From Small Species to Large Bio-Molecules
2021
A recompilation of applications of mesoporous silica nanoparticles in sensing from the last five years is presented. Its high potential, especially as hybrid materials combined with organic or bio-molecules, is shown. Adding to the multiplying effect of loading high amounts of the transducer into the pores, the selectivity attained by the interaction of the analyte with the layer decorating the material is described. Examples of the different methodologies are presented.
Structural characterization of iron oxide/hydroxide nanoparticles in nine different parenteral drugs for the treatment of iron deficiency anaemia by …
2013
Drug products containing iron oxide and hydroxide nanoparticles (INPs) are important for the treatment of iron deficiency anaemia. Pharmaceuticals prepared by the complexation of different kinds of INPs and carbohydrates have different physicochemical and biopharmaceutic characteristics. The increasing number of parenteral non-biological complex drugs (NBCD) containing iron requires physicochemical methods for characterization and enabling of cross comparisons. In this context the structure and the level of crystallinity of the iron phases may be connected to the in vitro and in vivo dissolution rates, which etiologically determine the therapeutic and toxic effects. X-ray powder diffraction…