Quinoxalineimide-Based Semiconducting Polymer Nanoparticles as an Effective Phototheranostic for the Second Near-Infrared Fluorescence Imaging and Photothermal Therapy

Authors：Zhu, Chunguang; Gao, Qian; Wang, Chunxiao; Shi, Linrui; Yin, Sen; Chen, Peiling; Guo, Ting; Hu, Zhenpeng; Ying, Lei^*

Source：ACS applied materials & interfaces, 2023, 15(24): 29396-29405.

DOI：10.1021/acsami.3c06853

• quinoxalineimide semiconductingpolymer
• nanoparticles
• NIR-II fluorescence imaging
• photothermal therapy
• multifunctional theranostics

Multifunctionaltheranostics play a critical role in improvingthe efficacy of photothermal therapy and tumor fluorescence imaging;however, they require the integration of complex components into asingle theranostic system, and their response in the second near-infrared(NIR-II) region is constrained by wavelengths of a photosensitizer.To address this issue, we herein developed a novel multifunctionalthiazole-fused quinoxalineimide semiconducting polymer (named PQIA-BDTT),which exhibits NIR-II fluorescence and photothermal properties. PQIA-BDTTnanoparticles achieved an impressively high photothermal conversionefficiency (72.6%) in laser (1064 nm)-induced photothermal therapyat a safe maximum permissible exposure, demonstrating their capabilityas an effective photothermal agent. Moreover, PQIA-BDTT nanoparticlescan be used as a reference for NIR-II fluorescence imaging under alow laser fluence. The tumor size and location in 4T1 mice intravenouslyinjected with the PQIA-BDTT nanoparticles could be preciselyidentified through NIR-II fluorescence imaging, which also exhibitedremarkable photothermal antitumor efficacy by in vitro and in vivo therapy.Overall, this study demonstrates that introducing a thiazole-fusedquinoxalineimide acceptor unit into a donor-acceptor conjugatedpolymer is an effective strategy for the synthesis of novel multifunctionaltheranostic systems, which provides a novel platform for designingtheranostic agents for biomedical applications.

• Institution
  南开大学; 中山大学