WazaGaY: An\nInnovative Aza-BODIPY-Derived Near-Infrared\nFluorescent Probe for Enhanced Tumor Imaging

Aza-BODIPYs represent\na class of fluorophores in which\nthe π-conjugated\nsystem is rigidified and stabilized by a boron atom. A promising strategy\nto enhance their fluorescence properties involves replacing the boron\natom with a metal ion. Here, we describe the synthesis and characterization\nof a water-soluble derivative where the metal is a gallium­(III) ion,\ntermed WazaGaY (water-soluble aza-GaDIPY). Water solubility is ensured\nby two ammonium substituents, inducing a bathochromic shift and a\nsignificant increase in quantum yield compared to that of the dimethylamino\nanalog. The cellular behavior of <b>WazaGaY-1</b> was observed\nacross different tumor cells. <i>In vivo</i>, the distribution\nand safety profiles were determined, and tumor uptake was assessed\nin various tumor types. Following intravenous injection, <b>WazaGaY-1</b> enabled clear discrimination of tumors engrafted subcutaneously\nin mice with high tumor-to-muscle ratios (ranging from 7 to 20), even\nin the absence of specific conjugation. Its potential as a contrast\nagent for fluorescence-guided surgery was confirmed.