Cerium dioxide nanoparticles affect in vitro fertilization in mice

Area of Science:

• Nanotechnology
• Reproductive Toxicology
• Environmental Health

Background:

• Cerium dioxide nanoparticles (CeO2NPs) possess catalytic and oxidative properties, leading to widespread use in diesel additives and cancer therapy.
• Limited data exists on CeO2NP toxicity, with no available information on their reproductive effects.

Purpose of the Study:

• To investigate the impact of CeO2NPs on in vitro fertilization (IVF) and assess their genotoxicity on mouse spermatozoa and oocytes.
• To determine the potential reproductive risks associated with low-dose exposure to CeO2NPs.

Main Methods:

• In vitro fertilization (IVF) assays were performed using mouse oocytes exposed to varying concentrations of CeO2NPs.
• Comet assay was employed to evaluate DNA damage in spermatozoa and oocytes.
• Transmission Electron Microscopy (TEM) was used to visualize nanoparticle uptake and localization.

Main Results:

• A significant decrease in fertilization rate was observed at a low CeO2NP concentration (0.01 mg.l⁻¹).
• Significant DNA damage was induced in mouse spermatozoa and oocytes by CeO2NPs at 0.01 mg.l⁻¹.
• TEM revealed nanoparticle endocytosis by cumulus cells and accumulation on gamete surfaces at high concentrations, but not within gamete cytoplasm.

Conclusions:

• CeO2NPs negatively impact in vitro fertilization and exhibit genotoxicity towards mouse spermatozoa and oocytes, even at low concentrations.
• Potential mechanisms for decreased fertilization include gamete genotoxicity, mechanical disruption, and oxidative stress induced by CeO2NPs.
• These findings underscore the reproductive toxicity of nanomaterials and the urgent need for comprehensive in vivo risk assessments.