Toward preparation of antibody-based imaging probe libraries for dual-modality positron emission tomography and fluorescence imaging Original Research Article

Two novel imaging agents trastuzumab-Cy5.5-CHX-A″ 1 and cetuximab-Cy7-CHX-A″ 2, bearing both a chelating moiety (CHX-A″) for sequestering metallic radionuclides (86Y or 111In) and the near infrared dye Cy5.5/Cy7, were prepared by a novel modular synthetic strategy as examples of dual-labeled, antibody-based imaging probe library. Fluorescent microscopy illustrated that 1 and 2 strongly bind to HER2-expressing cancer cells (e.g., NIH3T3–HER2+, SKOV-3) and to EGFR-expressing cancer cells (e.g., A431), respectively, thereby demonstrating that the functionality of the targeting moiety is conserved. Hence, the described novel synthesis strategy can be applied to engineer other tumor-targeted monoclonal antibody based probes for multimodality imaging.