Chlorination‐Mediated π–π Stacking Enhances the Photodynamic Properties of a NIR‐II Emitting Photosensitizer with Extended Conjugation

Abstract

NIR-II-emitting photosensitizers (PSs) have attracted great research interest due to their promising clinical applications in imaging-guided photodynamic therapy (PDT). However, it is still challenging to realize highly efficient PDT on NIR-II PSs. In this work, we develop a chlorination-mediated π-π organizing strategy to improve the PDT of a PS with conjugation-extended A-D-A architecture. The significant dipole moment of the carbon-chlorine bond and the strong intermolecular interactions of chlorine atoms bring on compact π-π stacking in the chlorine-substituted PS, which facilitates energy/charge transfer and promotes the photochemical reactions of PDT. Consequently, the resultant NIR-II emitting PS exhibits a leading PDT performance with a yield of reactive oxygen species higher than that of previously reported long-wavelength PSs. These findings will enlighten the future design of NIR-II emitting PSs with enhanced PDT efficiency.

Engineering of copper sulfide mediated by phototherapy performance

“…The ROS including singlet oxygen ( 1 O 2 ), hydroxyl radical (•OH), and peroxides (O 2 2À ) generated by light-activated PSs, which can cause changes in the morphology and functions of cells or biomolecules, leading to cancer cell killing and tumor ablation (Kuang et al, 2020;Yang et al, 2023;Zhou et al, 2016;Zou et al, 2021). PDT relies on the higher expression of ROS in tumors compared to healthy tissue, giving it noninvasive features, high selectivity, fewer side effects, and reduced drug resistance (Gu et al, 2023;Veeranarayanan et al, 2018). In spite of these advantages, PDT often suffers from inefficiency and necessitates repeated treatments due to the requirement of oxidative intermediate species in the hypoxic tumor microenvironment (M. Li, Xia, et al, 2018).…”