Antibody-target Binding in Living Tumors Using Macroscopy Fluorescence Lifetime Imaging

There is a continuing need to develop preclinical molecular imaging modalities to guide the development and optimization of targeted therapies in oncology. We have established Macroscopic Fluorescence Lifetime Imaging (MFLI) associated with Forster Resonance Energy Transfer (FRET) to report quantitatively on antibody-target engagement in live intact animals at the organ level. Here, we use FLI FRET imaging to quantify the binding of near infrared labeled antibody drugs to breast cancer cells or tumor xenografts. In combination with antibody engineering, this approach provides a robust analytical tool to optimize the binding and uptake of antibody-target binding during tumor progression and treatment.