Astatine-211-Labeled Gold Nanoparticles for Targeted Alpha-particle Therapy via Intravenous Injection

Abstract

Background: Alpha-particle radiotherapy has gained considerable attention owing to its potent anti-cancer effect. 211At, with a relatively short half-life of 7.2 h, emits an alpha particle within a few cell diameters with high kinetic energy, which damages cancer cells with high biological effectiveness. In this study, we investigated the intravenous injection of 211At-labeled gold nanoparticles (AuNPs) for targeted alpha-particle therapy (TAT). Results: Different kinds of surface-modified gold nanoparticles can be labeled with 211At in high radiochemical yield in 5 min, and no purification is necessary. In vivo biodistribution results showed the accumulation of 5 nm 211At-AuNPs@mPEG at 2.25 % injection dose per gram in tumors within 3 h via the enhanced permeability and retention effect. Additionally, we observed a long retention time in tumor tissues within 24 h. This is the first study to demonstrate the anti-tumor efficacy of 5 nm 211At-AuNPs@mPEG that can significantly suppress tumor growth in a pancreatic cancer model via intravenous administration. Conclusions: AuNPs are satisfactory carriers for 211At delivery, due to simple and efficient synthesis processes and high stability. Intravenous administration of 5 nm 211At-AuNPs@mPEG has a significant anti-tumor effect. This study provides a new framework for designing nanoparticles suitable for targeted alpha-particle therapy via intravenous injection.