Zhao Chengyan, Qu Chulin, Hu Yingzhe, Wu Fan, Liu Shaohai, Cai Fangjian, Chen Yuhang, Qiu Yudong, Shen Zhen
State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Department of Pancreatic and Metabolic Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine, Nanjing, 210008, China.
Adv Healthc Mater. 2024 Dec;13(32):e2402545. doi: 10.1002/adhm.202402545. Epub 2024 Sep 16.
Developing stable and efficient photothermal agents (PTAs) for the second near-infrared window (NIR-II, 1 000-1700 nm) photothermal therapy (PTT) is highly desirable but remains challenging. Herein, a facile strategy to prepare NIR-II nano-PTA based on the ionic N-doped nanographene hexapyrrolohexaazacoronene (HPHAC) is reported featuring a specific orbicular-donor-acceptor (O-D-A) structure. Oxidizing HPHAC 1 to dication 1 causes a substantial decrease in its band gap, leading to a shift in absorption from the confined UV region to a broad absorption range that reaches up to 1400 nm. The dication 1 exhibits global aromaticity and excellent stability. Theoretical investigation demonstrates that the strong NIR-II absorption of 1 is attributed to a distinct inner-to-outer intramolecular charge transfer. Encapsulating 1 with amphiphilic polymers results in water-soluble 1 NPs with retained optical characteristics. The 1 NPs exhibit exceptional biocompatibility, intense photoacoustic responses, and a high photothermal conversion efficiency of 72% under the 1064 nm laser irradiation, enabling efficient PTT of cancer cells. The "O-D-A" system on HPHAC, which is created by a simple redox approach, provides a novel strategy to construct efficient NIR-II photothermal materials through molecular engineering of nanographenes.
开发用于第二近红外窗口（NIR-II，1000 - 1700 nm）光热疗法（PTT）的稳定且高效的光热剂（PTA）是非常必要的，但仍然具有挑战性。在此，报道了一种基于离子型氮掺杂纳米石墨烯六吡咯并六氮杂蒄（HPHAC）制备NIR-II纳米PTA的简便策略，其具有特定的环状供体-受体（O-D-A）结构。将HPHAC 1氧化为二价阳离子1会使其带隙大幅降低，导致吸收从受限的紫外区域转移到高达1400 nm的宽吸收范围。二价阳离子1表现出全局芳香性和优异的稳定性。理论研究表明，1的强NIR-II吸收归因于独特的分子内从内到外的电荷转移。用两亲性聚合物包裹1得到具有保留光学特性的水溶性1纳米颗粒。1纳米颗粒表现出优异的生物相容性、强烈的光声响应以及在1064 nm激光照射下72%的高光热转换效率，能够实现对癌细胞的高效光热疗法。通过简单的氧化还原方法在HPHAC上构建的“O-D-A”体系，为通过纳米石墨烯的分子工程构建高效的NIR-II光热材料提供了一种新策略。
