Size-dependent radiosensitization of PEG-coated gold nanoparticles for cancer radiation therapy

摘要

Gold nanoparticles have been conceived as a radiosensitizer in cancerradiation therapy, but one of the important questions for primary drugscreening is what size of gold nanoparticles can optimally enhance radiationeffects. Herein, we perform in vitro and in vivo radiosensitization studies of4.8, 12.1, 27.3, and 46.6 nm PEG-coated gold nanoparticles. In vitro resultsshow that all sizes of the PEG-coated gold nanoparticles can cause asignificant decrease in cancer cell survival after gamma radiation. 12.1 and27.3 nm PEG-coated gold nanoparticles have dispersive distributions in thecells and have stronger sensitization effects than 4.8 and 46.6 nm particles byboth cell apoptosis and necrosis. Further, in vivo results also show all sizesof the PEG-coated gold nanoparticles can decrease tumor volume and weight after5 Gy radiations, and 12.1 and 27.3 nm PEG-coated gold nanoparticles havegreater sensitization effects than 4.8 and 46.6 nm particles, which can lead toalmost complete disappearance of the tumor. In vivo biodistribution confirmsthat 12.1 and 27.3 nm PEG-coated gold nanoparticles are accumulated in thetumor with high concentrations. The pathology, immune response, and bloodbiochemistry indicate that the PEG-coated gold nanoparticles do not causespleen and kidney damages, but give rise to liver damage and gold accumulation.It can be concluded that 12.1 and 27.3 nm PEG-coated gold nanoparticles showhigh radiosensitivity, and these results have an important indication forpossible radiotherapy and drug delivery.