Genotoxicity of nanoparticles evaluated using the in vitro micronucleus assay, a review of recent data^§

The in vitro micronucleus assay is a well-known and established component of the standard genotoxicity test battery. The growing use of nanomaterials around the world along with human exposure to them has increased the need for risk assessment with regard to safety, including potential genotoxicity. The in vitro micronucleus assay is one of the most used tests for evaluating the genotoxicity of nanomaterials. This review compiles studies since 2017 that performed assessments of micronucleus formation in vitro after cellular exposure to different nanomaterials. Genotoxicity of a broad range of nanomaterials including silver, cerium, zinc, gold, nickel, cadmium, titanium, carbon, and aluminum in different cell types were reviewed. While clear trends could be seen for some nanoparticle types like silver and cerium nanoparticles, others like gold nanoparticles showed mixed results. This review highlights the usefulness and effectiveness of the micronucleus assay for studying the genotoxicity of nanomaterials, in part, and is also careful to note that standard guidelines should be followed when conducting this assay in order to generate reliable and quality-driven data.