Physico-Chemical and Biological Properties of Arsenic Sulfide (As55S45) Nanosuspension Prepared by Milling

Nanosuspension based on melt-quenched arsenic sulfide of nominal As55S45 composition was prepared by nanomilling and tested as potential anticancer drug. Polyvinylpyrrolidone was used as steric stabilizer and inhibitor of agglomeration. Individual nanoparticles had average size of 192 nm (determined by photon cross-correlation spectroscopy) and had several times better dissolution ability in comparison with bulk As55S45. Effect of nanomilling is shown to be associated with formation of arsenic sulfide crystalline nanoparticles and free-volume entities located at the interface between nanoparticles and surrounding matrix as it follows from positron annihilation measurements. Cytotoxicity tests were performed using human melanoma cell line Bowes and confirmed high toxicity of the studied nanosuspension.