Au Nanoclusters Embedded in Polydopamine for Photothermal Radiotherapy on Non-Small-Cell Lung Cancer

Non-small-cell lung cancer (NSCLC) is characterized by high invasiveness, poor prognosis, and a high mortality rate. Single radiotherapy (RT) is ineffective in the treatment of NSCLC due to radio-resistance. Therefore, photothermal therapy (PTT) in combination with RT has been proposed, and PTT–RT synergistic therapy has been extensively explored for feasible cancer treatment. In this study, targeted Au nanoclusters embedded in polydopamine (AuNC/PDA–RGD) was constructed for PTT–RT combined therapy of NSCLC. The AuNC/PDA was prepared based on a one-pot seedless coassembly strategy. In the reaction, HAuCl 4 was directly reduced by dopamine to form the gold (Au) core, and dopamine was oxidized and spontaneously self-polymerized to form a PDA shell encapsulating the Au core. After modification with an active targeted Arg-Gly-Asp (RGD) peptide, AuNC/PDA–RGD was obtained, which showed good colloidal stability and low cytotoxicity. This nanosystem could be actively taken up by NSCLC (i.e., A549) cells via the RGD peptide-mediated internalization. Based on the high photothermal conversion capability of AuNC/PDA and the strong radiosensitivity of Au, the AuNC/PDA–RGD could be used for hyperthermia-synergized RT. The in vitro and in vivo experiments showed that the constructed nanosystem had an enhanced curative effect for the treatment of NSCLC by integrating PTT and RT compared with monotherapy. Our studies demonstrated that this AuNC/PDA–RGD nanoplatform has promising medical applications in cancer therapy.