In this paper, two novel AIE-active conjugated polymers were synthesized by Pd-catalyzed Suzuki coupling polymerization reaction. Interestingly, the obtained conjugated polymers could exhibit clear color-tunable AIE behavior by adjusting their intramolecular FRET pairs. Among them, P-1 with only one intramolecular FRET pair exhibited clear green-colored AIE fluorescence. As the second intramolecular FRET pair of a TPE moiety and a DTBT moiety was added (P-2), the AIE fluorescence color could be tuned from green to red. The Stokes shift also sharply increased from 125 nm to 255 nm. Furthermore, these AIE-active polymers could form stable conjugated polymer nanoparticles (CPNs) in an aqueous system and act as drug carriers for paclitaxel (PTX). Most importantly, PTX could be sufficiently released from these AIE-active CPNs and showed effective cytotoxicity on HeLa and A549 cells. Especially, these two AIE-active drug carriers were internalized by cells, and they also revealed their location with green or red colored AIE fluorescence. This study can provide a novel strategy for designing color-tunable AIE-active CPN-based drug carriers for self-indicating cancer therapy via changing intramolecular FRET pairs.

中文翻译：

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颜色可调的AIE活性共轭聚合物纳米颗粒作为药物载体，通过分子内FRET机制自我指示癌症治疗†

本文通过Pd催化的Suzuki偶联聚合反应合成了两种新型的AIE-活性共轭聚合物。有趣的是，获得的共轭聚合物可以通过调节其分子内FRET对表现出清晰的颜色可调AIE行为。其中，只有一个分子内FRET对的P-1呈现出清晰的绿色AIE荧光。作为TPE部分和DTBT部分的第二个分子内FRET对添加（P-2），可以将AIE荧光色从绿色调到红色。斯托克斯位移也从125 nm急剧增加到255 nm。此外，这些AIE活性聚合物可以在水性体系中形成稳定的共轭聚合物纳米颗粒（CPN），并充当紫杉醇（PTX）的药物载体。最重要的是，PTX可以从这些具有AIE活性的CPN中充分释放，并且对HeLa和A549细胞显示出有效的细胞毒性。尤其是，这两种具有AIE活性的药物载体已被细胞内化，并且还以绿色或红色的AIE荧光显示了它们的位置。这项研究可以提供一种新颖的策略，用于通过改变分子内FRET对来设计基于颜色可调AIE活性CPN的药物载体，用于自我指示的癌症治疗。