Toxicity of Copper Oxide (CuO) Nanoparticles on Human Blood Lymphocytes Evelyn Assadian 1,2 & Mohammad Hadi Zarei 2 & Ali Ghanadzadeh Gilani 1 & Mehrzad Farshin 2 & Hamid Degampanah 1 & Jalal Pourahmad 2 Received: 16 August 2017 /Accepted: 25 September 2017 # Springer Science+Business Media, LLC 2017 Abstract CuO nanoparticles (CuO-NPs) serve several impor- tant functions in human life, particularly in the fields of med- icine, engineering, and technology. These nanoparticles have been utilized as catalysts, semiconductors, sensors, gaseous and solid ceramic pigments, and magnet rotatable devices. Further use for CuO-NPs has been employed in the pharma- ceutical industry especially in the production of anti-microbial fabric treatments or prevention of infections caused by Escherichia coli and methicillin-resistant Staphylococcus aureus. Two key potential routes of exposure to CuO-NPs exist through inhalation and skin exposure. Toxicity of these nanoparticles has been reported in various studies; however, no study as of yet has investigated the complete cellular mech- anisms involved in CuO-NPs toxicity on human cells. The aim of this study was to determine the cytotoxicity of CuO- NPs on human blood lymphocytes. Blood lymphocytes were obtained from healthy male subjects through the use of Ficoll polysaccharide subsequently by gradient centrifugation. The following parameters were assayed in blood lymphocytes af- ter a 6-h incubation with different concentrations of CuO-NPs: cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, cellular glutathione levels, and mitochondrial and lysosomal damage. Our results demonstrate that CuO- NPs, in particular, decreased cell viability in a concentration- dependent manner and the IC50 determined was 382 μM. CuO-NP cytotoxicity was associated with significant increase at intracellular ROS level and loss of mitochondrial membrane potential and lysosomal membrane leakiness. Hence, CuO- NPs are shown to effectively induce oxidative stress in addi- tion to inflict damage on mitochondria and lysosomes in hu- man blood lymphocytes. Keywords CuO nanoparticles . Oxidative stress . Cytotoxicity . Mitochondria . Lysosomes Introduction Nanomaterials are materials with at least one dimension that is < 100 nm, such as nanoparticles (NP), nanotubes, nanocom- posites, and nanostructured [28]. Nanomaterials predominate- ly demonstrate uncommon chemical properties in comparison to macromaterials of similar chemical composition [31]. The unusual chemical properties of nanomaterials have given rise to further research in their potential use in commercial and industrial applications. Examples of such applications include fillers, drug carriers, pharmaceuticals, catalysts, biosensors, cosmetics, textiles, microelectronics, and environmental re- mediation [ 10 , 19 ]. As the potential application of nanomaterial use in new products expands, an impressive commercial market of $2.4 trillion was projected for the year 2014 [21]. The nanomaterials of importance for this paper are copper oxide nanoparticles (CuO-NPs), which are utilized as a catalyst and mixed with variety of materials to promote me- chanical characteristics [11]. CuO-NPs are widely produced and utilized as semiconductors, heat transfer fluids in machine tools, metal catalysts, and even in anti-microbial formulations Evelyn Assadian and Mohammad Hadi Zarei contributed equally to this study. * Hamid Degampanah h.dpanah@guilan.ac.ir * Jalal Pourahmad j.pourahmadjaktaji@utoronto.ca 1 Department of Chemistry, Faculty of Science, Guilan University, Guilan, P. O. Box: 41335-1914, Rasht, Iran 2 Department of Pharmacology and Toxicology, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, P.O. Box 14155-6153, Tehran, Iran Biol Trace Elem Res DOI 10.1007/s12011-017-1170-4