Titanium dioxide nanoparticles induce genotoxicity but not mutagenicity in golden mussel Limnoperna fortunei

• TiO2-NP can induce damage to DNA in haemocytes of Golden mussel.
• No mutagenic effects were observed in Golden mussel cells after TiO2-NP exposure.
• TiO2-NP induce oxidative damage to lipids and proteins in Golden mussel cells.

The widespread use of titanium dioxide nanoparticles (TiO2-NP) in consumer products is the cause of its appearance in wastewater and effluents, reaching the aquatic environment. The evaluation of the biological impact of TiO2-NP and the need to understand its ecotoxicological impact to the aquatic ecosystem are of major concern. Bivalve mollusks may represent a target group for nanoparticle toxicity. Limnoperna fortunei (golden mussel), a freshwater bivalve organism that has been employed in biomonitoring environmental conditions. Comet assay, micronucleus test and oxidative damage to lipids and proteins were performed after the golden mussel was exposed to TiO2-NP (1, 5, 10 and 50 μg mL−1). The results demonstrate that TiO2-NP can damage the DNA of haemocytes after 2 h of exposure and the genotoxic activity significantly increased after 4 h exposure to TiO2-NP, at all the TiO2-NP concentrations. TiO2-NP was ineffective in causing mutagenicity in the haemolymph cells of golden mussel. The increase in the lipid peroxidation levels and carbonyl proteins after the exposure to TiO2-NP indicates the induction of oxidative stress at 2 h exposure with similar results to all TiO2-NP concentrations, but these effects did not occur at 4 h exposure. These results demonstrated that, although TiO2-NP is not mutagenic to golden mussel, it does induce DNA damage and oxidative stress in these organisms.