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

Abstract

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 <i>via</i> 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 ⁶⁴Cu radiolabeling method by chemically reducing ⁶⁴Cu on the surface of polyethylene glycol (PEG)-stabilized Au NMs regardless of their shape and size. Our ⁶⁴Cu-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 ⁶⁴Cu 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