Comparison of the In Vitro and In Vivo Behavior of a Series of NIR-II-Emitting Aza-BODIPYs Containing Different Water-Solubilizing Groups and Their Trastuzumab Antibody Conjugates

The development of new fluorescent organic probes effective
in
the NIR-II region is currently a fast-growing field and represents
a challenge in the domain of medical imaging. In this study, we have
designed and synthesized an innovative series of aza-boron dipyrromethenes
emitting in the NIR-II region. We have investigated the effect of
different water-solubilizing groups not only on the photophysical
properties of the compounds but also on their in vitro and in vivo
performance after bioconjugation to the antibody trastuzumab. Remarkably,
we discovered that the most lipophilic compound unexpectedly displayed
the most favorable in vivo properties after bioconjugation. This underlines
the profound influence that the fluorophore functionalization approach
can have on the efficiency of the resulting imaging agent.