Metal nanomaterials such as bismuth oxide nanoparticles (Bi2O3NPs) have been extensively used in cosmetics, dental materials,pulp capping, and biomedical imaging. There is little knowledge about the health risk of Bi2O3NPs in humans, which warrants athorough toxicity investigation of Bi2O3NPs at the cellular level. In this experiment, we investigated the cytotoxic effect ofBi2O3NPs on human breast cancer (MCF-7) cells over 24 and 48 h. MCF-7 cells were exposed to Bi2O3NPs at varying doses(0.1, 0.5, 1.0, 5, 10, 20, 40 μg/mL) for 24 and 48 h. We assessed the toxicity of Bi2O3NPs by measuring its effect on the viabilityand oxidative stress biomarkers, e.g., GSH, SOD, and catalase in MCF-7 cells. The pro-apoptotic effects of Bi2O3NPs on MCF-7cells were determined via evaluating dysfunction of mitochondrial membrane potential (MMP), caspase-3 activity, externalizationof phosphatidylserine, and chromosome condensation. Furthermore, apoptotic cells were evaluated using 7-AAD fluorescence stainand Annexin V-FITC. Bi2O3NPs induced oxidative stress in MCF-7 cells in a time- and dose-dependent manner. Bi2O3NPsincreased the rate of both necrotic cells and apoptotic cells. In addition, the blue fluorescence of MCF-7 cells with condensedchromatin was increased in a time- and dose-dependent manner. In conclusion, the present study highlights the potential toxiceffects of Bi2O3NPs at the cellular level and suggests further investigation of Bi2O3NPs before any medical purposes.
Keywords Bi2O3NPs .MCF-7 cells . Cytotoxicity . Apoptosis