Killing G(+) or G(-) Bacteria? The Important Role of Molecular Charge in AIE-Active Photosensitizers
Killing G(+) or G(-) Bacteria? The Important Role of Molecular Charge in AIE-Active Photosensitizers
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DOI：
10.1002/smtd.202000046
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发表时间：
2020-07-01
期刊：
影响因子：
12.4
通讯作者：
Tang, Ben Zhong
中科院分区：
文献类型：
--
作者：
Shi, Xiujuan;Sung, Simon H. P.;Tang, Ben Zhong
细菌感染对人类健康构成严重威胁。光动力疗法是解决耐药菌问题的有效医学治疗方法。但制备出能同时产生高效荧光和活性氧的光敏剂并不容易。传统的ps在水介质中由于聚集引起的猝灭效应而表现出较差的性能，而具有聚集诱导发射（AIE）的发光源本质上可以实现高荧光和高效的ROS生成。此外，静电相互作用通常被认为是细菌初始靶向的原因。但对于AIE ps，很少考虑分子电荷对抗菌效率的影响。本文设计了两种具有相同发光核心但携带不同正电荷数的红发AIE ps，并研究了它们对革兰氏阳性（G(+)）和革兰氏阴性（G(-)）细菌的抗菌性能和杀伤机制。具有高效单线态产氧的AIE ps能够清晰成像并选择性杀灭哺乳动物细胞上的细菌。随着AIE ps正电荷的增加，对G（-）菌的抗菌效率提高很大，但对G（+）菌的抗菌效率可以忽略不计。本研究将为新型抗菌材料的合理设计提供新的思路。
Bacterial infections pose a serious threat to human health. Photodynamic therapy is an effective medical treatment to solve the problems raised by antibiotic resistant bacteria. But it is not easy to have photosensitizers (PSs) that can simultaneously produce efficient fluorescence and reactive oxygen species. Traditional PSs show compromised performances due to the aggregation-caused quenching effect in aqueous media, however, luminogens with aggregation-induced emission (AIE) can inherently achieve high fluorescence and efficient ROS generation. In addition, electrostatic interaction is generally accepted to be responsible for initial targeting of bacteria. But for AIE PSs, the roles of molecular charges on antibacterial efficiency are rarely considered. Herein, two red-emissive AIE PSs with the same luminogenic core but carrying different number of positive charges are designed, and their antibacterial performance and the killing mechanism toward Gram-positive (G(+)) and Gram-negative (G(-)) bacteria are investigated. The AIE PSs with highly efficient singlet oxygen generation can clearly image and selectively kill bacteria over mammalian cells. With the increase in the positive charges of AIE PSs, the improvement in antibacterial efficiency is great against G(-) bacteria, but it is negligible against G(+) bacteria. This research will provide new insight into the rational design of new antibacterial materials.