State Key Laboratory of Chemical Engineering, Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China.
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore, Singapore.
Angew Chem Int Ed Engl. 2020 Jul 13;59(29):11779-11783. doi: 10.1002/anie.202000338. Epub 2020 May 12.
In order to promote the development of photodynamic therapy (PDT), undesired side effects like low tumor specificity and the "always-on" phenomenon should be avoided. An effective solution is to construct an adaptive photosensitizer that can be activated to generate reactive oxygen species (ROS) in the tumor microenvironment. Herein, we design and synthesize a supramolecular switch based on a host-guest complex containing a water-soluble pillar[5]arene (WP5) and an AIEgen photosensitizer (G). The formation of the host-guest complex WP5⊃G quenches the fluorescence and inhibits ROS generation of G. Benefitting from the pH-responsiveness of WP5, the binding site between G and WP5 changes in an acidic environment through a shuttle movement. Consequently, fluorescence and ROS generation of the host-guest complex can be switched on at pH 5.0. This work offers a new paradigm for the construction of adaptive photosensitizers by using a supramolecular method.
为了促进光动力疗法（PDT）的发展，应该避免出现非靶向副作用，如低肿瘤特异性和“常开”现象。一种有效的解决方案是构建自适应光敏剂，它可以在肿瘤微环境中被激活以产生活性氧（ROS）。在这里，我们设计并合成了一种基于主客体配合物的超分子开关，该配合物包含一种水溶性的柱[5]芳烃（WP5）和一种 AIEgen 光敏剂（G）。主客体配合物 WP5⊃G 的形成猝灭了 G 的荧光并抑制了 ROS 的产生。得益于 WP5 的 pH 响应性，在酸性环境中，G 和 WP5 之间的结合位点通过穿梭运动发生变化。因此，在 pH 5.0 时可以开启主客体配合物的荧光和 ROS 生成。这项工作为使用超分子方法构建自适应光敏剂提供了一个新范例。
