In vitro and in vivo genotoxicity tests on fullerene C60 nanoparticles

There are several conflicting reports on the genotoxicity of fullerene C 60 in the literature. To determine the genotoxic potential of C 60 nanoparticles, we prepared stable nano-sized C 60 suspensions using 0.1% carboxymethylcellulose sodium (CMC-Na) or 0.1% Tween 80 aqueous solution. We conducted a bacterial reverse mutation test with Ames Salmonella typhimurium TA98, TA100, TA1535, and TA1537 strains and Escherichia coli strain and a chromosomal aberration test with cultured Chinese hamster CHL/IU cells in the presence and absence of metabolic activation under dark conditions and visible light irradiation using a stable C 60 nanoparticle suspension with CMC-Na. In addition, we performed a bone marrow micronucleus test using a stable C 60 nanoparticle suspension with Tween 80 on ICR mice. C 60 nanoparticles did not show a positive mutagenic response up to the maximum dose of 1000 μg/plate with any tester strain in the bacterial reverse mutation test regardless of metabolic activation and irradiation, although a slight but not significant increase in the number of revertants was observed in TA100 and WP2 uvrA /pKM101. No increase in the incidence of chromosomal aberrations was observed at any C 60 nanoparticle dose regardless of metabolic activation and irradiation in the chromosomal aberration test up to the maximum doses of 100 and 200 μg/mL. In addition, the micronucleus test showed that the in vivo clastogenic ability of the C 60 nanoparticles was negative up to the maximum dose of 88 mg/kg × 2. Therefore, we concluded that the stable and well-characterized C 60 nanoparticles did not have genotoxic ability in the bacterial reverse mutation assay, in vitro chromosome aberration assay, nor in vivo micronucleus assay.