High-Z metal encapsulated carbon dots for enhancing radiation therapy

Cancer is a major health problem worldwide. It is estimated that about 20 % people are diagnosed by cancer, and about 10% people die from cancer. Among the cancer patient, about 50% people receive radiation therapy (RT). Despite of advanced RT techniques, the maximum dose is still limited by the radiation tolerance of surrounding normal tissues. Radiosensitizers are often used along with RT to overcome the dose limitation. With emerging of nanotechnology, high-Z nanoparticles (HZNPs) have attracted attention as a radiosensitizer due to their strong photoelectric effect. Until now, many HZNPs have been proposed, but the most HZNPs nanoparticles are limited to clinical translation due to suboptimal pharmacokinetics, low cellular accumulation, and heavy metal toxicity. Here, high-Z metal loaded carbon dots (M@Cdots) are explored as a novel type of radiosensitizer. The carbon dots (Cdots) are only about 3nm, and they are chemically and biologically inert. Therefore, other than enhanced radiation therapy efficacy, minimal systematic toxicity can be expected.