In Vivo Studies of Laser-Ablated Gold Nanoparticles as Dose Enhancers for Binary Radiotherapy of Cancer

Gold nanoparticles (GNPs) are actively used as dose enhancing agents in combination with X-ray irradiation. The synthesis of gold nanoparticles by laser ablation has a number of advantages over other methods (for example, the possibility of preparing a chemically pure solution and a relatively low production cost when synthesis is scaled up). An additional antitumor effect from the combined use of gold nanoparticles synthesized by laser ablation and X-rays was studied. Mice transplanted subcutaneously with Ca755 syngeneic adenocarcinoma were used for the study. The tumor was irradiated at a dose of 10 Gy in 30 min after injection of GNPs. As a result, 66% of complete regressions were found in the experimental group of mice within 210 days after transplantation, while there were no regressions of tumor nodes in the control irradiated group. The absorbed dose to the vascular walls with gold nanoparticles in the bloodstream was evaluated as 26.8 Gy owing to local energy release.