Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, Jiangsu, P. R. China.
J Mater Chem B. 2020 Aug 26;8(33):7356-7364. doi: 10.1039/d0tb01107j.
The preferable photoconversion tunability of conjugated polymers (CPs) is of great interest in cancer phototherapy. However, very few molecular design strategies have been developed for achieving CPs with highly efficient photoconversion performance. Herein, a rational design of near-infrared (NIR) Pt-acetylide conjugated polymer CP3 with highly efficient photoconversion behaviors for synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) was demonstrated. CP3 containing boron dipyrromethene (BDP) units displayed intense absorption peaks in the NIR region, which were red-shifted approximately 60 nm compared to the corresponding small-molecule precursor of BDP. Compared with control polymers CP1 and CP2, after the introduction of Pt into CP3, the triplet state, which benefits the generation of reactive oxygen species for photodynamic therapy, was identified clearly in both CP3 and the prepared CP3 nanoparticles (CP3-NPs) by ultrafast femtosecond transient absorption (fs-TA) spectroscopy. Notably, different from the traditional nonradiative decay channel with lifetime of 1.1 ps in CP3, CP3-NPs possess an additional nonradiative decay channel with lifetime of 10 ps, both of which contribute to the superior photothermal conversion effect upon 808 nm irrradiation. All these photoconversion performances lead to excellent tumor ablation. This study elucidates the excited-state dynamics in Pt-acetylide CPs, which provide an insightful understanding and valuable guidelines for the future design of high-performance theranostic agents based on CPs for synergistic cancer phototherapy.
具有高效光转换性能的共轭聚合物（CPs）的光转化可调谐性是癌症光疗中非常感兴趣的。然而，很少有分子设计策略被开发出来用于实现具有高效光转化性能的 CPs。本文中，设计了一种具有高效光转化行为的近红外（NIR）Pt-炔键共轭聚合物 CP3，用于协同光动力疗法（PDT）和光热疗法（PTT）。含硼二吡咯甲川（BDP）单元的 CP3 在近红外区域显示出强烈的吸收峰，与 BDP 的相应小分子前体相比，其红移约 60nm。与对照聚合物 CP1 和 CP2 相比，将 Pt 引入 CP3 后，通过超快飞秒瞬态吸收（fs-TA）光谱清楚地鉴定出 CP3 和制备的 CP3 纳米粒子（CP3-NPs）中的三重态，这有利于光动力疗法中活性氧的产生。值得注意的是，与 CP3 中寿命为 1.1ps 的传统非辐射衰减通道不同，CP3-NPs 具有寿命为 10ps 的额外非辐射衰减通道，两者都有助于在 808nm 照射下产生优越的光热转换效果。所有这些光转化性能都导致了优异的肿瘤消融。本研究阐明了 Pt-炔键 CPs 的激发态动力学，为基于 CPs 的高效治疗药物的未来设计提供了有价值的见解和指导原则，以用于协同癌症光疗。
