1. Reversible pH-switchable NIR-II nano-photosensitizer for precise imaging and photodynamic therapy of tumors.
- Author
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Chai, Yun, Sun, Ye, Sheng, Zhijia, Zhu, Yanyan, Du, Tianyou, Zhu, Bingjian, Yu, Hui, Dong, Bin, Liu, Yi, and Wang, Hai-Yan
- Subjects
PHOTODYNAMIC therapy ,TUMOR microenvironment ,NANOTECHNOLOGY ,PHOTOSENSITIZERS ,SMALL molecules ,REACTIVE oxygen species - Abstract
Photodynamic therapy (PDT) has attracted widespread attention from researchers as an emerging cancer treatment method. There have been many reports on various types of NIR-II photosensitizers for imaging and treatment of tumor sites. However, there are few reports on the development of NIR-II organic small molecule photosensitizers that have intelligent response to the tumor microenvironment, precise imaging, real-time treatment, and high biocompatibility. In this work, we developed a series of NIR-II photosensitizers (RBTs) with near-infrared excitation, good photostability, and large Stokes shift. Among them, RBT-Br exhibited higher reactive oxygen species (ROS) generation efficiency due to the introduction of halogen heavy atoms to enhance intersystem crossing (ISC). It is noteworthy that RBT-Br can generate singlet oxygen (
1 O 2) and superoxide anion radicals (• O 2− ) simultaneously under 730 nm laser. Subsequently, we used molecular engineering technology to construct three pH-responsive NIR-II photosensitizers (RBT-pHs) by utilizing the closure of the lactam ring, among which RBT-pH-1 (p K a = 6.78) is able to be directionally activated under the stimulation of tumor micro-acid environment, with its fluorescence emission window reaching 933 nm. Subsequently, RBT-pH-1 NPs encapsulated in DSPE-mPEG 5k were applied for PDT treatment of mouse tumors. The results showed that RBT-pH-1 NPs were activated by the acidic tumor microenvironment and generated ROS under laser excitation, exhibiting precise tumor imaging and significant tumor growth inhibition. We look forward to these multifunctional NIR-II organic small molecule photosensitizers providing a more efficient approach for clinical treatment of tumors. A reversible pH-switchable NIR-II nano-photosensitizer RBT-pH-1 NPs (p K a = 6.76) is developed for precise imaging and PDT therapy of mouse tumors, which can be effectively used for targeted enrichment and activation of tumor micro-acid environments. The results show that this NIR-II photosensitizer generates ROS through tumor micro-acid environment stimulation and laser triggering, showing precise tumor imaging guidance and significant tumor growth inhibition. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2024
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