Eliminating Active Species by Endohedral Metallofullerenol in vitro and in vivo

We previously demonstrated that gadolinium endohedral metallofullerenol Gd@C82(OH)22 nanoparticles had high inhibitory activity on growth of malignant tumor in vivo by uncertain mechanism(s). The activities of enzymes associated with the metabolism of reactive oxygen species (ROS) were decreased in the tumor-bearing mice by intraperitoneally injection of Gd@C82(OH)22 nanoparticles . In current study, systemic investigation of the potential function of Gd@C82(OH)22 nanoparticles found that it expressed direct scavenging activity toward active species. Electron spin resonance (ESR) spectroscopy, the state-ofart technique to measure chemical active species that have one or more unpaired electrons in parallel, was employed to measure free radicals scavenging activities of Gd@C82(OH)22 nanoparticles in vitro. Pre-treatment with Gd@C82(OH)22 nanoparticles significantly reduced ESR signal of various of reactive oxygen species. In addition, Gd@C82(OH)22 nanoparticles demonstrated extensively scavenging activities of active species measured in vivo, which was consistent with reduced progression of cancer cells treated with Gd@C82(OH)22 nanoparticles. In summary, results obtained in this study revealed strong active species-scavenging activities of Gd@C82(OH)22 nanoparticles in vitro and in vivo. Scavenging activities of hydroxylated Gd@C82(OH)22 nanoparticles was systemically measured in different milieu, and demonstrated the inhibition of tumor progression by treatment with Gd@C82(OH)22 nanoparticles likely due to eliminating active species.