WazaGaY: An Innovative Aza-BODIPY-Derived Near-Infrared Fluorescent Probe for Enhanced Tumor Imaging.

Aza-BODIPYs represent a class of fluorophores in which the π-conjugated system is rigidified and stabilized by a boron atom. A promising strategy to enhance their fluorescence properties involves replacing the boron atom with a metal ion. Here, we describe the synthesis and characterization of a water-soluble derivative where the metal is a gallium(III) ion, termed WazaGaY (water-soluble aza-GaDIPY). Water solubility is ensured by two ammonium substituents, inducing a bathochromic shift and a significant increase in quantum yield compared to that of the dimethylamino analog. The cellular behavior of was observed across different tumor cells. , the distribution and safety profiles were determined, and tumor uptake was assessed in various tumor types. Following intravenous injection, enabled clear discrimination of tumors engrafted subcutaneously in mice with high tumor-to-muscle ratios (ranging from 7 to 20), even in the absence of specific conjugation. Its potential as a contrast agent for fluorescence-guided surgery was confirmed.