College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P.R. China.
ACS Appl Mater Interfaces. 2022 Jan 26;14(3):4417-4422. doi: 10.1021/acsami.1c19698. Epub 2022 Jan 10.
Near-infrared (NIR) targeted cell imaging has become a research hotspot due to the advantages of deeper tissue penetration, minimal interference from the background signals, and lower light damage. Herein, we report a multivalent supramolecular aggregate with NIR fluorescence emission, which was fabricated from triphenylamine derivatives (TPAs), cucurbit[8]uril (CB[8]), Si-rhodamine (SiR), and hyaluronic acid (HA). Interestingly, possessing a rigid luminescent core and cationic phenylpyridinium units linked by flexible alkyl chains, the tripaddle hexacationic TPA could bind with CB[8] at a 2:3 stoichiometric ratio to form a network-like multivalent assembly with enhanced red luminescence. Such organic two-dimensional network-like aggregate further co-assembled with the energy acceptor SiR and cancer cell targeting agent HA, leading to nanoparticles with NIR emission at 675 nm via an intermolecular energy transfer pathway. Furthermore, the obtained multivalent supramolecular aggregate was successfully applied in lysosome targeted imaging toward A549 cancer cells, which provides a convenient strategy for NIR targeted cell imaging.
近红外（NIR）靶向细胞成像是近年来的研究热点，因为它具有更深的组织穿透能力、最小的背景信号干扰和更低的光损伤。在此，我们报告了一种具有近红外荧光发射的多价超分子聚集体，它由三苯胺衍生物（TPAs）、葫芦[8]脲（CB[8]）、硅罗丹明（SiR）和透明质酸（HA）制备而成。有趣的是，具有刚性发光核心和由柔性烷基链连接的阳离子苯基吡啶鎓单元的三脚六阳离子 TPA 可以与 CB[8]以 2:3 的化学计量比结合，形成具有增强红光发射的网络状多价组装体。这种有机二维网络状聚集体进一步与能量受体 SiR 和癌细胞靶向剂 HA 共组装，通过分子间能量转移途径导致在 675nm 处发射近红外光的纳米颗粒。此外，所得的多价超分子聚集体成功地应用于 A549 癌细胞的溶酶体靶向成像，为近红外靶向细胞成像提供了一种便捷的策略。
