Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach

Nanoparticles (NP) are potentially repmtoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2: 10 to 10,000 mu g.L-1) and silver NP (Ag: 0.25 to 250 mu g.L-1) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO2 NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO2 NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.

Automated summary

This study evaluated the impact of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2) and silver nanoparticles (Ag) on the sperm of gilthead seabream. The results showed that there were no significant changes in sperm motility, head morphometry, mitochondrial function, and DNA integrity, except for supra environmental concentration of Ag nanoparticles. However, exposure to TiO2 nanoparticles led to depletion of antioxidants, while exposure to Ag nanoparticles resulted in decreased SOD. These findings suggest that TiO2 and Ag nanoparticles induce low levels of spermiotoxicity without proven relevant ecological impacts.