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Organotinsulfides Sn 4 S 4 R 6 (R = methyl, n-butyl and phenyl) were employed as single-source precursors for nanometric tin sulfides. The residues obtained after pyrolysis in hydrogen, nitrogen and oxygen were characterized by X-ray diffraction, 119 Sn Mössbauer spectroscopy, scanning electron microscopy and X-ray electron probe microanalysis. The results clearly showed the formation of tetragonal SnO 2 (rutile-type structure) in oxygen and pure phase orthorhombic γ -Sn 2 S 3 in nitrogen when Sn 4 Bu 4 S 6 (2) was employed as precursor. The 119 Sn Mössbauer spectroscopic results were very important in the elucidation of the decomposition process. Compound 2 is the best starting material for the process.

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Selenized Saccharomyces cerevisiae cells are used as a nutritional supplement for humans and animals since they contain large amounts of selenomethionine. Although it has been discussed less frequently, they also have a considerable quantity of selenium nanoparticles (Se-NP). Se-NP were generated inside cells after 48 h of incubation with sodium selenite; these nanoparticles were shown to have a spherical morphology, with an estimated size of 20-30 nm, and were mainly made up of Se. The type of Se-NP produced inside the cells depends on the new protein synthesis. They are amorphous, and are generated regardless of the presence of light or oxygen. After its intracellular generation, Se-NP move to the extracellular compartment, without compromising membrane integrity in aerobic conditions. The release of Se-NP from cells was time dependent.

Selenium nanoparticles (SeNPs) were synthesized by irradiating a solution containing sodium selenite (Se +4 ) as the precursor in YPG liquid medium with gamma-rays. Spherical particles were formed after reactions of sodium selenite with hydrated electrons (e aq -) and hydrogen radicals (H • ) produced following water radiolysis. No hazardous reducing agents were employed. The obtained nanoparticles were morphologically characterized, and their physicochemical and structural parameters were analyzed.SeNPs characterization showed all selenium in the Se 0 state. We incubated Saccharomyces cerevisiae cells with the SeNPs for 24 h and then challenged the cells with ionizing radiation. After radiation exposure, cells were assessed for cell viability, lipid peroxidation, protein carbonylation, free radical generation, and total sulfhydryl content. The synthesized SeNPs were considered safe and less toxic at the concentration employed than the same selenite concentration. Except for the protein carbonylation results, there were no other signi cant modi cations in viability or the oxidative stress parameters in SeNP-treated cells. It was concluded that 1 mM of the synthesized SeNPs does not trigger oxidative stress. Furthermore, we veri ed that SeNPs attenuate the reactive oxygen species generation after in vitro ionizing radiation exposure. These observations open up tremendous possibilities for radiosensitizer development. HighlightsSynthesis of selenium nanoparticles with gamma irradiation and sodium selenite Generation of spherical, amorphous, and zero-valent selenium nanoparticlesIn vitro nanoparticle treatment reduces reactive oxygen species after irradiation Selenium nanoparticles are safe, nontoxic, not provoking oxidative stress in vitro Selenium nanoparticles as possible platform for radiosensitizers development

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