Small molecular interaction-based fluorescence enhancement for second near-infrared imaging

This study described a new strategy to enhance second near-infrared (NIR-II) fluorescence intensity. NIR-II liposomes were prepared by thin film hydration method and their fluorescence properties were evaluated. The efficacy of the optimized liposome was then evaluated with low dose and irradiation. Indocyanine green-IR1061 liposome exhibited higher fluorescence intensity (∼fourfold than IR1061 liposome) with the red-shifted emission. The intensity of indocyanine green-IR1061 cationic liposome was enhanced to approximately tenfold, which allowed us to perform angiography with lower doses and less exposure time. We report a new and efficient way to enhance NIR-II fluorescence intensity. This could be used to acquire high temporal resolution and signal-to-background ratio fluorescence imaging.