Well-characterized, nanoparticle reference materials are urgently needed for nanomaterial toxicity studies. The National Institute of Standards and Technology has developed three gold nanoparticle (AuNP) reference materials (10 nm, 30 nm, 60 nm) to address this need. We evaluated AuNPs for their potential to induce oxidative damage to DNA using calf-thymus DNA in a cell-free model as well as in a HepG2 cell model. For both models, after a specified AuNP incubation period, sample and control DNA was isolated, washed and enzymatically digested into component nucleosides. DNA damage was assessed based on the specific and sensitive measurement of four oxidatively-modified DNA lesions (8-hydroxy-2¿-deoxyguanosine, 8-hydroxy-2¿-deoxyadenosine, (5¿S)-8,5¿-cyclo-2¿-deoxyadenosine and (5¿R)-8,5¿-cyclo-2¿-deoxyadenosine) using liquid chromatography/tandem mass spectrometry. Significantly elevated, dose-dependent DNA damage was not detected in either the acellular or cellular experimental model. In addition, the AuNPs demonstrated minimal effects on cell viability, cell inflammatory response and cell cycle function in the HepG2 culture model. These data suggest that the NIST AuNPs could potentially serve as suitable negative-control nanoparticulate reference materials for in vitro and in vivo genotoxicity testing platforms investigating oxidative damage to DNA, as well as other forms of DNA damage.
Pub Type: Journals
DNA damage, genotoxicity, gold nanoparticles, mass spectrometry, modified nucleosides, nanomaterials