Sulforaphane-assisted preparation of tellurium flower-like nanoparticles.

A new method for the fabrication of flower-like tellurium nanoparticles is reported. It is based on the reduction of tellurite precursor by products generated during decomposition of sulforaphane at elevated temperature in aqueous medium. These species and other organic molecules present in the reaction mixture are being adsorbed on the surface of tellurium nuclei and govern further tellurium growth in the form of nanoflowers. The obtained particles have been characterized by a range of physicochemical techniques. It was shown that the average size of the nanoflower particles is ca. 112 nm, and they are composed of smaller domains which are ca. 30 nm in diameter. The domains are crystalline and consist of trigonal tellurium as shown by x-ray diffraction, Raman spectroscopy and high resolution transmission electron microscopy. The tellurium nanoflowers were examined from the perspective of their potential anticancer activity. The in vitro cell viability studies were conducted on breast cancer (MDA-MB-231, MCF-7) and normal cell lines (MCF-10A) employing MTT and CVS assays. It was shown, that the nanoflowers exhibit considerable cytotoxicity against cancer cells which is ca. 3-7 times higher than that observed for reference normal cells. The preliminary in vivo investigations on rats revealed that the nanoflowers accumulate predominantly in pancreas after intraperitoneal administration, without observable negative behavioral effects.