AbstractConventional cyanine dyes with a symmetric structure are “always‐on”, which can easily accumulate in the liver and display high liver background fluorescence, inevitably interfering the accurate diagnosis and therapy in extrahepatic diseases. We herein report a platform of NIR‐II non‐symmetric cyanine (NSCyanine) dyes by harnessing a non‐symmetric strategy, which are extremely sensitive to pH/viscosity and can be activated via a “dual‐key‐and‐lock” strategy. These NSCyanine dyes with a low pKa (<4.0) only show weak fluorescence at lysosome pH (key1), however, the fluorescence can be completely switched on and significantly enhanced by intracellular viscosity (key2) in disease tissues, exhibiting high target‐to‐liver ratios up to 19.5/1. Notably, high‐contrast phototheranostics in extrahepatic diseases are achieved, including intestinal metastasis‐imaging, acute gastritis‐imaging, bacteria infected wound healing, and tumor ablation via targeted combined photothermal therapy and chemotherapy.
摘要 具有对称结构的传统
氰基
染料是 "常开型 "的,容易在肝脏中蓄积并显示较高的肝背景荧光,不可避免地干扰肝外疾病的准确诊断和治疗。我们在此报告了一种利用非对称策略的近红外-II 非对称
氰基(NSCyanine)
染料平台,这种
染料对 pH 值/粘度极为敏感,可通过 "双键锁定 "策略激活。这些低 pKa(4.0)的 NSCyanine
染料只在溶酶体 pH 值(key1)下显示微弱的荧光,但在疾病组织中,荧光可以完全开启,并因细胞内粘度(key2)而显著增强,显示出高达 19.5/1 的靶肝比。值得注意的是,在肝外疾病中实现了高对比度光热疗法,包括肠道转移成像、急性胃炎成像、细菌感染伤口愈合,以及通过联合光热疗法和化疗靶向消融肿瘤。