Hepatic ultrastructural alterations induced by copper oxide nanoparticles: In vivo electron microscopy study

Copper oxide nanomaterials (CuO NPs) have been widely utilized in many fields, including antibacterial materials, anti-tumor, osteoporosis treatments, imaging, drug delivery, cosmetics, lubricants for metallic coating, the food industry, and electronics. Little is known about the potential risk to human health and ecosystems. The present work was conducted to investigate the ultrastructural changes induced by 20 +/- 5 nm CuO NPs in hepatic tissues. Adult healthy male Wister albino rats were exposed to 36 intraperitoneal (ip) injections of 25 nm CuO NPs (2 mg/kg bw). Liver biopsies from all rats under study were processed for transmission electron microscopy (TEM) processing and examination for hepatic ultrastructural alterations. The hepatic tissue of rats exposed to repeated administrations of CuO NPs exhibited the following ultrastructural alterations: extensive mitochondrial damage in the form of swelling, crystolysis and matrix lysis, formation of phagocytized bodies and myelin multilayer figures, lysosomal hyperplasia, cytoplasmic degeneration and vacuolation, fat globules precipitation, chromatin clumping, and nuclear envelope irregularity. The findings indicated that CuO NPs interact with the hepatic tissue components and could induce alterations in the hepatocytes with the mitochondria as the main target organelles of copper nanomaterials. More work is recommended for better understanding the pathogenesis of CuO NPs.