ROS-induced cytotoxicity of colloidal copper nanoparticles in MCF-7 human breast cancer cell line: an in vitro study

Copper is known for its bactericidal properties since ancient time. Development of copper nanoparticle (CNP) based antimicrobial products has generated interest in studying their toxicological properties. In this article, we have investigated the ROS (reactive oxygen species)–induced cytotoxicity of colloidal CNPs on MCF-7 human breast cancer cells. To understand the dependence of nanoparticle’s anticancer potential on their per batch yield, three identical sets of CNPs with similar physical properties with hydrodynamic size (11–14 nm) were prepared by chemical reduction method with per batch yield of 0.2 g, 0.3 g, and 0.4 g. Dose-dependent toxicity of as-synthesized (i.e., without any post preparation treatment) CNPs was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay for CNP concentrations of 0.001–100 μg/mL. Strong dose-dependent toxicity was observed in all CNPs batches, which was because of the mitochondrial damage in MCF-7. Cytotoxicity in MCF-7 exposed to CNPs was observed due to rupture of cell membrane and shrinkage as well as oxidative stress induced by reactive oxygen species (ROS). IC50 values of CNPs were independent of per batch yield of CNPs. This confirms that increase in CNPs yield from 0.2 to 0.4 g has no negative correlation with their cytotoxic response. The ability to scale up the nanoparticle yield with strong dose-dependent cytotoxicity makes CNPs potential candidate for the development of anticancer drugs.