§High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
ACS Nano. 2015 May 26;9(5):5117-24. doi: 10.1021/acsnano.5b00287. Epub 2015 Apr 15.
(19)F MRI has higher selectivity but lower sensitivity than (1)H MRI for in vivo diagnosis. Therefore, to avoid using a high injection dose of the (19)F probe while, in the meantime, maintaining the high sensitivity of (19)F MRI has remained challenging. Local self-assembly and disassembly of (19)F nanoparticles could be one of the "smart" strategies to achieve this goal. Herein, we report a dual-functional probe 1 for glutathione (GSH)-controlled self-assembly and subsequent legumain (Lgmn)-controlled disassembly of its nanoparticles (i.e., 1-NPs). Self-assembly and disassembly of 1-NPs confer (19)F magnetic resonance (MR) signals "off" and "on", respectively. Employing this strategy, we successfully applied 1 for consecutive detections of GSH and Lgmn in vitro and in cells, imaging Lgmn activity in HEK 293T tumors in zebrafish at a low dosage under 14.1 T.
（19）F MRI 比（1）H MRI 具有更高的选择性，但灵敏度较低，适用于体内诊断。因此，避免使用高剂量的（19）F 探针，同时保持（19）F MRI 的高灵敏度一直是具有挑战性的。（19）F 纳米粒子的局部自组装和自拆卸可能是实现这一目标的“智能”策略之一。在此，我们报告了一种双功能探针 1，用于谷胱甘肽（GSH）控制的自组装和随后的组织蛋白酶 L（Lgmn）控制的纳米粒子（即 1-NPs）的拆卸。1-NPs 的自组装和拆卸分别赋予（19）F 磁共振（MR）信号“关闭”和“开启”。利用该策略，我们成功地在体外和细胞中连续检测了 GSH 和 Lgmn，并在斑马鱼的 HEK 293T 肿瘤中以 14.1 T 以下的低剂量成像 Lgmn 活性。
