Qi Qiang, Jiang Zhongxiu, Li Jianqing, Wei Haoyu, Su Deliang, Gong Yi, Wang Hongdi, Zhao Zujin, Zhao Xiaofeng, Zhou Jian
College of Material, Chemistry and Chemical Engineering, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.
State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.
Adv Healthc Mater. 2025 Jul;14(19):e2500966. doi: 10.1002/adhm.202500966. Epub 2025 Jun 2.
The near-infrared second window (NIR-II) offers excellent spatial resolution and tissue penetration, drawing attention to NIR-II laser-excited photothermal therapy (PTT) and NIR-II fluorescence imaging. However, integrating these two applications poses challenges due to safe laser power and reagent dosage constraints. To overcome these issues, we proposed modifying the ternary copolymer backbone by substituting 4H-cyclopenta[2,1-b:3,4-b']dithiophene (DTC) with 4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene (IDT), enabling a transition from a photothermal to a fluorescence agent. Adjusting molar ratios of donor and acceptor units coupling with either DTC or IDT in the polymer significantly affects their photophysical properties. Among the synthesized copolymers, PDTC-253 showed optimal photothermal performance, while PIDT-253 exhibited high fluorescence quantum yields. Both were used to create biocompatible nanoparticles (NPs). Under 1064 nm laser irradiation, PDTC-253 NPs effectively eliminated 4T1 cancer cells in vitro. In vivo studies with mice bearing 4T1 tumors showed that PDTC-253 NPs could accumulate at the tumor sites, facilitating the treatment of tumors of varying sizes under 1064 nm laser irradiation, while PIDT-253 NPs provided long-term tumor tracking through NIR-II fluorescence imaging, and clearly visualizing blood vessels even at wavelengths reaching 1500 nm. This approach advances the development of effective phototheranostic agents for tumor PTT and fluorescence imaging in the NIR-II window.
近红外第二窗口（NIR-II）具有出色的空间分辨率和组织穿透能力，这使得NIR-II激光激发的光热疗法（PTT）和NIR-II荧光成像备受关注。然而，由于安全激光功率和试剂剂量的限制，将这两种应用结合起来具有挑战性。为了克服这些问题，我们提出通过用4,9-二氢-s-茚并[1,2-b:5,6-b']二噻吩（IDT）取代4H-环戊并[2,1-b:3,4-b']二噻吩（DTC）来修饰三元共聚物主链，从而实现从光热剂到荧光剂的转变。调整聚合物中与DTC或IDT偶联的供体和受体单元的摩尔比会显著影响它们的光物理性质。在合成的共聚物中，PDTC-253表现出最佳的光热性能，而PIDT-253具有高荧光量子产率。两者都被用于制备生物相容性纳米颗粒（NPs）。在1064 nm激光照射下，PDTC-253 NPs在体外有效消除了4T1癌细胞。对携带4T1肿瘤的小鼠进行的体内研究表明，PDTC-253 NPs可以在肿瘤部位积聚，便于在1064 nm激光照射下治疗不同大小的肿瘤，而PIDT-253 NPs通过NIR-II荧光成像提供长期的肿瘤追踪，甚至在波长达到1500 nm时也能清晰地可视化血管。这种方法推动了用于NIR-II窗口肿瘤PTT和荧光成像的有效光热诊疗剂的开发。
