Gold nanoparticles for radiosensitizing and imaging of cancer cells

Radiation therapy is a regular treatment modality in cancer therapy. Despite being a beneficial strategy, the radiation doses are limited, in large part because of the occurrence of inadvertent toxicity in the surrounding healthy tissues/organs. Among efforts to minimize the unwanted side effects in normal tissues and sensitize tumor tissues/organs to radiation, utilization of the high atomic number material such as noble metals (e.g., gold, platinum) appears to provide promising outcome as radiation sensitizers. In addition, growing advances in the field of nanomaterials/biomedical sciences have facilitated their applications as radiosensitizers in radiotherapy. Multifunctional nanoparticles (NPs), in particular, gold NPs (AuNPs), which offer a great capacity for increasing photoelectric interactions at lower energy levels, are able to enhance the impacts of radiotherapy by increasing the energy deposition in tumor tissues. Modified AuNPs, with higher mass-energy coefficient in soft tissue at the keV energy range, have reached huge interests in the concurrent radiotherapy of various malignancies. The AuNPs have a great potential to be translated into the clinical applications in various cancer treatments. In this current study, we review the most recent works in the development of gold-based radiosensitizing agents and discuss the utilized approaches for the radiotherapy and articulate their impacts in cancer therapy.