On the use of radioisotopes to study the possible synthesis by magnetron sputtering of bimetallic nanoparticles

An approach using physical vapor deposition technology to produce nanoparticles (NPs) containing radioactive atoms and the methodology to transfer them in pure water is investigated. NPs are synthesized by magnetron sputtering at high pressure and radioactive atoms are loaded on magnetron cathodes prior to sputtering. The technique was tested for gold cathode loaded with 57/58Co and 195/196Au. Linked to biological vector molecules, the nanoparticles can be used to enhance diagnostic sensitivity in medical imaging or to treat cancer. Sizes and morphologies of the NPs were analyzed by electron microscopy, UV-Visible spectroscopy and atomic absorption spectroscopy. Results show well dispersed NPs with sizes varying between 5 and 10 nm. Activities of these NPs were measured with a CAPINTEC well counter and a High Purity Germanium detector system. Centrifugation analyses also demonstrate that the choice of the activated metal which can be alloyed with NPs plays an important role in the synthesis. This was confirmed by the Au–Co phase diagram that shows that cobalt cannot be included efficiently in the gold NPs conversely to gold

Are stirring and sonication pre-dispersion methods equivalent for in vitro toxicology evaluation of SiC and TiC?

The evolution of the particle size distribution and the surface composition of silicon carbide and titanium carbide nanoparticle (NP) dispersions were studied. The pre-dispersions were prepared using two commonly used protocols for dispersion: stirring and sonication. Two dispersants were investigated (water and Pluronic F108 1 %) at two stages: predispersion and during in vitro assays. Our data show that for each tested condition, different time-dependent results for the surface chemical composition as well as size and percentage of the agglomerates and the primary particles are observed. De-agglomeration and successive or simultaneous cleaning-wrapping cycles of the nanomaterial are observed and are related to the dispersion method and the medium as well as to the chemical stability of the NP surface. Biological response during in vitro assessment was also performed for one given pre-dispersion time condition and demonstrates that the preparation method significantly alters the resultsKavli Institute of NanoScienceApplied Science