Investigation of different targeting decorations effect on the radiosensitizing efficacy of albumin-stabilized gold nanoparticles for breast cancer radiation therapy.

Gold nanoparticles (GNPs) radiosensitizing effect strongly depends on the tumor targeting efficacy. The aim of this study is to identify the most ideal targeting decoration for BSA-GNPs according to tumor targeting and biodistribution. Therefore, three well-known targeting agents (folic acid, glucose, and glutamine) were utilized for BSA-GNPs decoration. Glucose-BSA-GNPs, glutamine-BSA-GNPs, and folic acid-BSA-GNPs were synthesized and then, characterized by Fourier-transform infrared spectroscopy and UV-Spectrometry. Then, the GNPs were intravenously injected 10 mg/kg to 4T1 breast tumor-bearing mice to evaluate biodistribution and radiosensitizing effects. Folic acid and glutamine decorations could significantly increase tumor targeting efficacy of BSA-GNPs as 2.1 and 2.4 times increase of gold accumulation was detected in comparison with BSA-GNPs. They exhibited the highest radiosensitizing efficacy and caused about 33% decrease in tumors volume in comparison with BSA-GNPs after 6 Gy radiation therapy. All the GNPs were completely biocompatible. Although, glutamine-BSA-GNPs and folic acid-BSA-GNPs could significantly enhance the tumor targeting and radiosensitizing efficacy of BSA-GNPs, did not exhibit any significant advantage over each other. Therefore, glutamine and folic acid decoration of BSA-GNPs can significantly increase the tumor targeting and therapeutic efficacy as radiosensitizer.