Table 1 Inclusion and exclusion criteria, and search terms used in the literature review

Inclusion criteria

 1. In vitro studies performed using validated assays:

  • Mammalian cell micronucleus (MN) assay

  • Chromosomal aberration (CA) assay

  • Mammalian gene mutation assays: tests using hypoxanthine–guanine phosphoribosyltransferase (Hprt) or xanthine phosphoribosyltransferase (Xprt), and thymidine kinase (Tk) genes, including the mouse lymphoma assay (MLA)^a

 2. In vivo studies performed using validated assays:

  • In vivo comet assay

  • Mammalian erythrocyte MN assay

  • Mammalian CA assay

  • Gene mutation assays

 3. In vivo studies performed by inhalation, oropharyngeal aspiration, intratracheal instillation, dermal, oral exposure, or any type of injection

Exclusion criteria

 4. The words fibers, nanotubes, graphene, and therapy, were excluded from the search for in vivo studies of metal-containing NPs, as the search produced a considerable number of publications unrelated to the topic of this review

 5. Full text was not available in English through conventional sources

Search terms

 6. In vitro nanofibers: (nanotubes OR nanofibers OR nanofibres) AND (Hprt OR Xprt OR Tk OR micronucleus OR "chromosomal aberration*") AND (human OR mouse OR rat OR mammalian)

 7. In vivo nanofibers: (nanofibers OR nanofibres OR nanotubes) AND genotox* AND (“in vivo” OR rats OR mice)

 8. In vitro metal-containing NPs: nanoparticles AND (Hprt OR Xprt OR Tk OR micronucleus OR "chromosomal aberration*") AND (human OR mouse OR rat OR mammalian) NOT thioketal

 9. In vivo metal-containing NPs: nanoparticles AND (comet OR micronucleus OR aberrations OR "gene mutation") AND (inhalation OR aspiration OR instillation OR dermal OR oral OR gavage OR injection) AND metal NOT (fibers OR fibres OR graphene OR nanotubes OR therapy)^b