Facile Synthesis of Zn-Doped Bi(2)O(3) Nanoparticles and Their Selective Cytotoxicity toward Cancer Cells

[Image: see text] Bismuth (III) oxide nanoparticles (Bi(2)O(3) NPs) have shown great potential for biomedical applications because of their tunable physicochemical properties. In this work, pure and Zn-doped (1 and 3 mol %) Bi(2)O(3) NPs were synthesized by a facile chemical route and their cytotoxicity was examined in cancer cells and normal cells. The X-ray diffraction results show that the tetragonal phase of β-Bi(2)O(3) remains unchanged after Zn-doping. Transmission electron microscopy and scanning electron microscopy images depicted that prepared particles were spherical with smooth surfaces and the homogeneous distribution of Zn in Bi(2)O(3) with high-quality lattice fringes without distortion. Photoluminescence spectra revealed that intensity of Bi(2)O(3) NPs decreases with increasing level of Zn-doping. Biological data showed that Zn-doped Bi(2)O(3) NPs induce higher cytotoxicity to human lung (A549) and liver (HepG2) cancer cells as compared to pure Bi(2)O(3) NPs, and cytotoxic intensity increases with increasing concentration of Zn-doping. Mechanistic data indicated that Zn-doped Bi(2)O(3) NPs induce cytotoxicity in both types of cancer cells through the generation of reactive oxygen species and caspase-3 activation. On the other hand, biocompatibility of Zn-doped Bi(2)O(3) NPs in normal cells (primary rat hepatocytes) was greater than that of pure Bi(2)O(3) NPs and biocompatibility improves with increasing level of Zn-doping. Altogether, this is the first report highlighting the role of Zn-doping in the anticancer activity of Bi(2)O(3) NPs. This study warrants further research on the antitumor activity of Zn-doped Bi(2)O(3) NPs in suitable in vivo models.