Chelator-Free (64)Cu-Integrated Gold Nanomaterials for Positron Emission Tomography Imaging Guided Photothermal Cancer Therapy

[Image: see text] Using positron emission tomography (PET) imaging to monitor and quantitatively analyze the delivery and localization of Au nanomaterials (NMs), a widely used photothermal agent, is essential to optimize therapeutic protocols to achieve individualized medicine and avoid side effects. Coupling radiometals to Au NMs via a chelator faces the challenges of possible detachment of the radiometals as well as surface property changes of the NMs. In this study, we reported a simple and general chelator-free (64)Cu radiolabeling method by chemically reducing (64)Cu on the surface of polyethylene glycol (PEG)-stabilized Au NMs regardless of their shape and size. Our (64)Cu-integrated NMs are proved to be radiochemically stable and can provide an accurate and sensitive localization of NMs through noninvasive PET imaging. We further integrated (64)Cu onto arginine-glycine-aspartic acid (RGD) peptide modified Au nanorods (NRs) for tumor theranostic application. These NRs showed high tumor targeting ability in a U87MG glioblastoma xenograft model and were successfully used for PET image-guided photothermal therapy.