Development of Polar BODIPY-Tetrazines for Rapid Pretargeted\nFluorescence Imaging

Polar BODIPY-tetrazine\ndyes were developed and clicked in vivo\nto a preaccumulated <i>trans</i>-cyclooctene-modified anti-TAG72\nmonoclonal antibody CC49 (CC49-TCO). The in vivo click performance\nwas evaluated using an in-house developed ex vivo blocking assay.\nAll tested polar BODIPY structures exhibited excellent in vivo binding,\nconfirming that the turn-on tetrazine dyes successfully clicked in\nvivo to pretargeted CC49-TCO. Fluorescence imaging showed high tumor-to-muscle\nratios of 4:1. This proof-of-concept study indicates that the pretargeting\nconcept based on turn-on probes could be used for cancer treatments,\nsuch as photodynamic or -thermal therapy.