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

TL;DR

This study investigates how the size of PEG-coated gold nanoparticles affects their ability to enhance radiation therapy in cancer treatment, finding that 12.1 and 27.3 nm sizes are most effective.

Contribution

It provides a comprehensive comparison of different gold nanoparticle sizes for radiosensitization, identifying optimal sizes for cancer therapy.

Findings

12.1 and 27.3 nm nanoparticles show stronger radiosensitization effects.

All sizes decrease tumor volume after radiation, with optimal sizes nearly eliminating tumors.

Nanoparticles accumulate in tumors without causing significant spleen or kidney damage.

Abstract

Gold nanoparticles have been conceived as a radiosensitizer in cancer radiation therapy, but one of the important questions for primary drug screening is what size of gold nanoparticles can optimally enhance radiation effects. Herein, we perform in vitro and in vivo radiosensitization studies of 4.8, 12.1, 27.3, and 46.6 nm PEG-coated gold nanoparticles. In vitro results show that all sizes of the PEG-coated gold nanoparticles can cause a significant decrease in cancer cell survival after gamma radiation. 12.1 and 27.3 nm PEG-coated gold nanoparticles have dispersive distributions in the cells and have stronger sensitization effects than 4.8 and 46.6 nm particles by both cell apoptosis and necrosis. Further, in vivo results also show all sizes of the PEG-coated gold nanoparticles can decrease tumor volume and weight after 5 Gy radiations, and 12.1 and 27.3 nm PEG-coated gold nanoparticles have greater sensitization effects than 4.8 and 46.6 nm particles, which can lead to almost complete disappearance of the tumor. In vivo biodistribution confirms that 12.1 and 27.3 nm PEG-coated gold nanoparticles are accumulated in the tumor with high concentrations. The pathology, immune response, and blood biochemistry indicate that the PEG-coated gold nanoparticles do not cause spleen 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 show high radiosensitivity, and these results have an important indication for possible radiotherapy and drug delivery.