Copper oxide nanoparticles (CuO NPs) are extensively used in various industrial and commercial applications. Despite their wide application may lead to the contamination of marine ecosystem, their potential environmental effects remain to be determined. Toxicity assessment studies have primarily focused on investigating the effects of CuO NPs on fertilization success and embryo development of different sea urchin species while the impact on sperm quality have never been assessed. In this line, this study aims to assess the effects of CuO NPs on the spermatozoa of the sea urchin Paracentrotus lividus.

After sperm exposure to CuO NPs, biomarkers of sperm viability, cytotoxicity, oxidative stress, and genotoxicity as well as morphology were evaluated. Results showed that CuO NPs exposure decreased sperm viability, impaired mitochondrial activity and increased the production of reactive oxygen species (ROS) and lipid peroxidation. Furthermore, CuO NPs exposure caused DNA damage and morphological alterations. Together with the antioxidant rescue experiments, these results suggest that oxidative stress is the main driver of CuO NP spermiotoxic effects. The mechanism of toxicity is here proposed: the spontaneous generation of ROS induced by CuO NPs and the disruption of the mitochondrial respiratory chain lead to production of ROS that, in turn, induce lipid peroxidation and DNA damage, and result in defective spermatozoa up to induce sperm cytotoxicity. Investigating the effects of CuO NPs on sea urchin spermatozoa, this study provides valuable insights into the mechanism of reproductive toxicity induced by CuO NPs.

氧化铜纳米颗粒（CuO NPs）广泛用于各种工业和商业应用。尽管它们的广泛应用可能导致海洋生态系统的污染，但其潜在的环境影响仍有待确定。毒性评估研究主要集中在研究CuO NPs对不同海胆物种受精成功和胚胎发育的影响，而从未评估过对精子质量的影响。在这一方面，本研究旨在评估CuO NP对海胆Paracentrotus lividus精子的影响。

精子暴露于CuO NPs后，评估了精子生存力，细胞毒性，氧化应激和遗传毒性以及形态的生物标志物。结果表明，CuO NPs暴露会降低精子活力，削弱线粒体活性，并增加活性氧（ROS）的产生和脂质过氧化作用。此外，CuO NPs暴露会导致DNA损害和形态变化。结合抗氧化剂抢救实验，这些结果表明氧化应激是CuO NP精子毒性作用的主要驱动力。本文提出了毒性机理：CuO NPs自发产生ROS和线粒体呼吸链的破坏导致ROS的产生，进而引起脂质过氧化和DNA损伤，并导致精子缺陷，从而导致ROS的产生。精子的细胞毒性。研究CuO NPs对海胆精子的影响，这项研究为CuO NPs诱导的生殖毒性机理提供了有价值的见解。