Fabrication And Size-Denendent Toxicity And Radiation Enhancement Of PEG-Coated Gold Nanoparticles

Malignant tumors is the major disease that causes of death in the world. The cure of the tumor has been the goal of medicine. And radiation therapy is one of the main treatment of tumors. A key objective in tumor radiation and X-ray irradiation therapy is to reduce the dose and the damage to healthy tissues and organs. Gold nanoparticles(GNPs) are top candidates as drug carriers and radiotherapy enhancers due to the combination of small size and leaky vasculature of tumor tissues.We fabricated GNPs through chemical reduction reaction, and investigated the growth mechanism of GNPs. Then modified the surface of GNPs with SH-PEG to reduce the toxicity of GNPs. Analyzed their stability in plasma. We carried out size dependent toxicity and cytotoxicity in HeLa cells, H22cells and HepG2cells. Enhancement of radiation effect by137Cs was made.The results showed that PEG-GNPs with different sizes will reduce the cell survival rate of different concentrations. The reasons were the coated agent and s-ize effect for GNPs. In vivo experiments showed that the toxicity of3.3nm-PEG-GNPs and30.5nm-PEG-GNPs were lower than that of14.4nm-PEG-GNPs and52.3nm-PEG-GNPs. Clonogenic assay of cells in vitro showed that the particles coul d generated radiosensitizing effect on cell.Cytotoxicity and radiosensitivity of PEG-GNPs were complex, and affected by many factors, the particle size, surface coating, etc. It had a great significance in th-is study for understanding the toxicity and radiation sensitizer of different sizes of nanoparticles. Provide a basis support to explore the GNPs in the subject of toxicit-y and the safe use.