Silica nanoparticles administered at the maximum tolerated dose induce genotoxic effects through an inflammatory reaction while gold nanoparticles do not

► We examined the potential of gold and silica nanoparticles to cause genotoxic effects. ► Gold nanoparticles did not cause genotoxic effects in any of the assays. ► No effects were observed in the in vitro micronucleus assay with silica nanoparticles. ► Silica nanoparticles caused DNA damage in the in vivo Comet and micronucleus assays only at the MTD. ► Oxidative and inflammatory markers demonstrate tissue damage driven inflammation.