Cu_2- Se nanoparticles (Cu_2- Se NPs) mediated neurotoxicity via oxidative stress damage in PC-12 cells and BALB/c mice

Cu_2- Se nanoparticles (Cu_2- Se NPs) are widely used for optical diagnostic imaging and photothermal therapy due to their strong near-infrared (NIR) optical absorption. With the continuous expansion of applications using Cu_2- Se NPs, their biosafety has received increasing attention in recent years. Cu_2- Se NPs can enter the brain by crossing the blood-brain barrier, but the neurotoxicity of NPs remains unclear. The present investigation provides direct evidence that the toxicity of Cu_2- Se NPs can be specifically exploited to kill rat pheochromocytoma PC-12 cells (a cell line used as an in vitro model for brain neuron research) in dose- and time-dependent manners. These cytotoxicity events were accompanied by mitochondrial damage, adenosine triphosphate (ATP) depletion, production of oxidizing species (including reactive oxygen species (ROS), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂)), as well as reductions in antioxidant defense systems (glutathione (GSH) and superoxide dismutase (SOD)). Moreover, our in vivo study also confirmed that Cu_2- Se NPs markedly induced neurotoxicity and oxidative stress damage in the striatum and hippocampal tissues of BALB/c mice. These findings suggest that Cu_2- Se NPs induce neurotoxicity in PC-12 cells and BALB/c mice via oxidative stress damage, which provides useful information for understanding the neurotoxicity of Cu_2- Se NPs.