Ligand engineering of Au<sub>44</sub>nanoclusters for NIR-II luminescent and photoacoustic imaging-guided cancer photothermal therapy
Yang Ge, Xueluer Mu, Xinxin Pan, Ying Tang, Qiaofeng Yao, Yaru Wang, Fuyi Jiang, Fanglin Du, Jianping Xie, Xianfeng Zhou, Xun Yuan
Abstract
NCs in the second near-infrared window (NIR-II, 1000-1700 nm) with aromatic photoacoustic (PA)/photothermal molecules through click chemistry. This design bypasses the incompatibility dilemma between photoluminescence (PL) attributes and PA/photothermal properties because the rigidity of the PA/photothermal molecules can lead to aggregation-induced emission (AIE) of the Au(i)-ligand shell of the Au NCs by constraining their nonradiative relaxation. Benefiting from strong NIR-II PL with emissions at 1080 and 1240 nm, high photothermal conversion efficiency (65.12%), low cytotoxicity, appropriate renal clearance, and enhanced permeability and retention (EPR) effect, the as-designed Au NC-based theranostic probe achieves ultradeep NIR-II PL/PA imaging-guided cancer photothermal therapy (PTT). Remarkably, 16 days after photothermal treatment guided by NIR-II PL/PA imaging, mice were all healed without tumor recurrence, while the average life span of the mice in the control groups was only 17-21 days. This study is interesting because it provides a paradigm for designing a metal NC-based theranostics probe, and it may add fundamentally and methodologically to noninvasive imaging-guided disease therapy.