Highly Stable Near-Infrared II Luminescent Diradicaloids for Cancer Phototheranostics
Lina Feng, Yanyan Tuo, Zipeng Wu, Weijing Zhang, Chunbin Li, Bo Yang, Lingxiu Liu, Jianye Gong, Guoyu Jiang, Weibing Hu, Ben Zhong Tang, Limin Wu, Jianguo Wang
Abstract
Near-infrared II (NIR-II) phototheranostic agents have become prominent agents for the early diagnosis and precise treatment of cancer. Organic open-shell diradicaloids with distinct structure and narrow band gap are promising candidates for phototherapeutic agents due to their strong spin-coupling effect and NIR light-harvesting capacity. However, achieving stable and efficient NIR-II luminescent diradicaloids is crucial yet rather challenging considering their high chemical reactivity and self-absorption. Herein, two highly stable NIR-II luminescent diradicaloids, 2PhNVDPP and PhNVDPP, were successfully fabricated by employing an acceptor planarization/π-conjugation extension and donor rotation strategy. After encapsulation into water-dispersible nanoparticles (NPs), 2PhNVDPP NPs exhibit NIR-II luminescence, high PCE of 53%, and improved photo/heat stability. In vivo experiments with 2PhNVDPP NPs demonstrated the clear visualization of blood vessels and tumors, as well as the successful NIR-II imaging-guided photothermal ablation of tumors. This study not only develops a pioneering stable diradicaloid phototherapeutic agent with NIR-II luminescence but also provides a unique perspective for the effectiveness of multimodal anticancer therapy.