BACKGROUND Tungsten carbide nanoparticles are being explored for their use in the manufacture of hard metals. To develop nanoparticles for broad applications, potential risks to human health and the environment should be evaluated and taken into consideration. OBJECTIVE We aimed to assess the toxicity of well-characterized tungsten carbide (WC) and cobalt-doped tungsten carbide (WC-Co) nanopa...

In this study, apoptosis and related signaling induced by WC-Co nanoparticles were investigated in JB6 cells and rat lung macrophages. Electron spin resonance (ESR) and fluorescent staining indicated that both WC-Co nanoparticles and fine particles stimulated reactive oxygen species (ROS) generation. Catalase exhibited an inhibitory effect on WC-Co nanoparticle-induced ROS as well as mitochondr...

Nano-sized particles of ceramic and metallic materials are generated by high-tech industrial activities, and can be generated from worn-out replacement and prosthetic implants. The interaction with the human body of such nanoparticles has been investigated, with a particular emphasis on innate defence mechanisms. Human macrophages (PMA-differentiated myelomonocytic U-937 cells) were exposed in ...

Oxide nanoparticles of Fe-Co-Ni were prepared in six different compositions by co-precipitation method. The as-synthesized nanoparticles were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron microscope (FESEM), Fourier Transform Infrared (FT-IR) and Vibrating Sample Magnetometer  (VSM). It was found that the nanoparticles had mean crystalline size of 30-55 nm and spher...

To improve the performance of nanostructured calcium carbonate in gene delivery, a hydrophilic polysaccharide, alginate, was added to calcium carbonate co-precipitation systems to form alginate/CaCO(3)/DNA nanoparticles. The size and ζ-potential of the nanoparticles were measured by a zetasizer. Due to the existence of alginate chains which retarded the growth of calcium carbonate based co-prec...

Monodisperse cobalt nanoparticles are synthesized via a high-temperature thermal decomposition method in the presence of oleic acid and triphenylphosphine. The as-synthesized nanoparticles are stable against further deep oxidation when they are kept in heptane .C7H16/. Time-dependent XPS studies indicate that oxidation of the as-synthesized cobalt nanoparticles in air is slow. The valence chang...

SYNLETT 2005, No. 4, pp 0545–055904.03.2005 Advanced online publication: 22.02.2005 DOI: 10.1055/s-2005-862380; Art ID: A36604ST © Georg Thieme Verlag Stuttgart · New York Abstract: In this account, we survey our work on the use of transition metal nanoparticles as catalysts in Pauson–Khand-type reactions. Cobalt nanoparticles and Co/Ru, Co/Rh, and Co/Pd heterobimetallic nanoparticles have been...

We report a combined experimental and computational study on the critical role of surfactants in the nucleation and growth of Co nanoparticles synthesized by chemical routes. By varying the surfactant species, Co nanoparticles of different morphologies under similar reaction conditions (e.g., temperature and Co-precursor concentration) were produced. Depending on the surfactant species, the gro...

Carbon-encapsulated cobalt (Co@C) nanoparticles, with a tunable structure, were synthesized by chemical vapor deposition using Co nanoparticles as the catalyst and supported on a water-soluble substrate (sodium chloride), which was easily removed by washing and centrifugation. The influences of growth temperature and time on the structure and magnetic properties of the Co@C nanoparticles were s...

Fully biodegradable and surface-functionalized poly(D,L-lactide) (PLA) nanoparticles have been prepared by a co-precipitation technique. Novel amphiphilic random copolyesters P(CL-co-γXCL) were synthesized by controlled copolymerization of ε-caprolactone and ε-caprolactone substituted in the γ-position by a hydrophilic X group, where X is either a cationic pyridinium (γPyCL) or a non-ionic hydr...