Drug-delivery microcapsules tagged with zirconium-89 can be tracked by PET imaging

Polymer and radionuclide chemists report major advance in microcapsule drug delivery systems. Their microcapsules -- labeled with radioactive zirconium-89 -- are the first example of hollow polymer capsules capable of long-term, multiday positron emission tomography imaging in vivo. In previous work, the researchers showed that the hollow capsules could be filled with a potent dose of the cancer drug doxorubicin, which could then be released by therapeutic ultrasound that ruptures the microcapsules.