On the toxicity of copper oxide nanoparticles

Background: Copper oxide nanomaterials (CuO NPs) have been widely utilized in many fields, including antibacterial materials, anti-tumor, osteoporosis treatment, imaging, drug delivery, cosmetics, lubricants for metallic coating, food industry, and electronics with probable potential risk to human health and the ecosystems.

Objectives: The present work was conducted to investigate the toxicity of CuO NPs in the vital organs. Methods: Adult healthy male Wister Albino rats were exposed to 36 intraperitoneal (ip) injections of CuO NPs (2 mg/kg bw). All rats were subjected to morphometric, biochemical, haematological, behavioural, histological, histochemical and transmission electron microscopy (TEM) and examinations.

Results: Chronic exposure to CuO NPs induced morphometric alterations mainly body weigh reduction and organ indices, back arching, Urinary bladder ballooning, lung abscess and renal calculi formation.

The renal tissues of rats exposed to chronic CuO NPs demonstrated proximal renal tubules degeneration, glomerular atrophy and hypercellularity, interstitial edema, renal blood vessels dilatation and congestion, occasional fibrosis and hyaline casts precipitation. In addition, chronic subjection to CuO NPs induced mitochondrial swelling and crystolysis, hydropic degeneration, lysosomal hypertrophy, apoptotic activity, nuclear deformity, chromatin dissolution and nucleoli enlargement. Moreover, erosion and disorganization of the apical microvilli, basement membrane thickening and crystals precipitation the glomerular capillary were also detected.

On the other hand, the hepatic tissue of rats exposed to nano copper oxide exhibited hepatocytes injury, Kupffer cells hyperplasia, sinusoidal alterations and inflammatory cells inflammation. Moreover, the injured hepatocytes showed mitochondrial swelling, cristolysis and matrix lysis, formation of phagocytized bodies and myelin multilayer figures, lysosomal hyperplasia, cytoplasmic degeneration and vacuolation, and hepatocytes nuclear alteration. The findings indicate that copper oxide nanoparticles interact with the hepatic tissue components and could induce alterations in the liver with the mitochondria as the main target organelles to the toxicity of copper nanomaterials. More work is recommended for better understanding the pathogenesis of copper oxide nanoparticles and nano products.