Inhibitory effects of aqueous nanoparticle suspensions of [60] fullerene derivatives on bacterial growth

In recent years, the biological activities of fullerene nanoparticles have received extensive attention, but there are few reports on aqueous nanoparticle suspensions of [60] fullerene derivatives and bacterial growth. The antibacterial effects of two aqueous nanoparticle suspensions of [60] fullerene derivatives, bis-methanophosphonate fullerene(BMPF) and fullerol, were studied for the first time by the bacterial growth inhibition test. The results show that both nano-BMPF and nano-fullerol could dose-dependently inhibit the growth of the gram-positive bacteria S. aureus under dark condition. The 50% inhibition concentrations of these two nanoparticle suspensions were 9.1 and 4.2 μmol/L, respectively. In order to explore their antibacterial mechanism, three different scavengers of reactive oxygen species were tested, including singlet oxygen inhibitor azide, hydroxyl free radical inhibitor mannitol and superoxide anion inhibitor superoxide dismutase. It was revealed that the antibacterial activity of nano-fullerol probably did not involve reactive oxygen species, but superoxide anion might be involved in the antibacterial action of nano-BMPF. In addition, both aqueous nanoparticle suspensions couldn't inhibit the growth of the gram-negative bacteria E. coli under dark condition. These results indicate that nanoparticles of different fullerene derivatives prevented bacterial growth via distinct mechanisms, and they might be potentially used in the biomedical field as novel antibacterial reagents.