Nuclear and Fluorescent Labeled PD-1-Liposome-DOX-64Cu/IRDye800CW Allows Improved Breast Tumor Targeted Imaging and Therapy.

The overexpression of programmed cell death-1 (PD-1) in tumors as breast cancer makes it a possible target for cancer imaging and therapy. Advances in molecular imaging, including radionuclide imaging and near-infrared fluorescence (NIRF) imaging, enable the detection of tumors with high sensitivity. In this study, we aim to develop a novel PD-1 antibody targeted positron emission tomography (PET) and NIRF labeled liposome loaded with doxorubicin (DOX) and evaluate its application for in vivo cancer imaging and therapy. IRDye800CW and 64Cu were conjugated to liposomes with PD-1 antibody labeling, and DOX was inside the liposomes to form theranostic nanoparticles. The 4T1 tumors were successfully visualized with PD-1-Liposome-DOX-64Cu/IRDye800CW using NIRF/PET imaging. The bioluminescent imaging (BLI) results showed that tumor growth was significantly inhibited in the PD-1-Liposome-DOX-treated group than the IgG control. Our results highlight the potential of using dual-labeled theranostic PD-1 mAb-targeted Liposome-DOX-64Cu/IRDye800CW for the management of breast tumor.