Redox-driven speciation and colloid formation contribute the in vivo chemistry and organ deposition of Astatine-211

These results identify redox-driven speciation and subsequent hydrolysis/aggregation as key chemical processes contributing to the in vivo behavior of free ²¹¹At. Understanding and controlling astatine redox chemistry is therefore critical for improving the stability, safety, and translational development of ²¹¹At-based radiopharmaceuticals.