Ultrasmall Pt Clusters Reducing Radiation-Induced Injuries via Scavenging Free Radicals

High energy ionizing radiation was widely used in medical diagnosis and cancer radiation therapy. The high dose of X ray or γ ray can cause the damage of cancerous tissue as well as healthy tissue during therapy. Therefore, it is urgent to develop chemical agents to protect the healthy tissue from high energy ray invasion. Here, the ultrasmall Pt clusters were employed as the anti-radiation agents for protecting healthy cells and improving survival rate of irradiated mice. It was found that Pt clusters can reduce the DNA damages in irradiated cells. In vivo experiments show that the Pt clusters treatment can improve the survival rate of irradiated mice up to 30%. As a contrast, only-irradiated mice without Pt clusters treatment completely died after 15 days. The detailed biological experiments showed that Pt clusters can recover the bone marrow DNA level and superoxide dismutase activities via scavenging free radicals. Importantly, the ultrasmall Pt clusters can be excreted rapidly by kidney and do not cause long-term toxicity.