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

Aim: This study described a new strategy to enhance second near-infrared (NIR-II) fluorescence intensity. Materials & methods: 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 in vivo with low dose and irradiation. Results: Indocyanine green-IR1061 liposome exhibited higher fluorescence intensity (similar to 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. Conclusion: 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.