Liver injury long-term monitoring and fluorescent image-guided tumor surgery using self-assembly amphiphilic donor-acceptor NIR-II dyes

Real-time monitoring of liver dysfunction represents a significant unmet demand in clinical and preclinical research. The second near-infrared window (NIR-II, 1000-1700 nm) fluorescent imaging is an attractive method for biomedical imaging and may be a promising approach for liver dysfunction monitoring. Herein, we designed and synthesized a small-molecule NIR-II dye TQT 1009 with an asymmetric donor-acceptor (D-A) core. By introducing four kinds of polyethylene glycol (PEG) with different length and molecular weights (nK, n = 0.5, 2, 5, 10) to TQT1009, the dye was self-assembled into different nanoparticles named as TQP nK with regulated size and controllable circulation lifetime in vivo. In general, TQP nK showed a super high contrast ratio for blood vessels, bones, intestines, lymph, and tumor imaging. The best-selected probe, TQP 10K, exhibited ultralong in vivo circulation time (>96 h) which was suitable for long-term quantitative monitoring of liver and vessel function at a single dose, implying the excellent prospects compared with ICG, which was quickly eliminated in blood within a few minutes. Meanwhile, TQP 10K also achieved NIR-II surgical navigation of tumor in an extended time window (>7 d). Overall, our results demonstrate the self-assembly PEGylated amphiphilic TQP nK provide a new probe design strategy for liver function monitoring and image-guided tumor surgery in a prolonged time window.