Cancer is a highly fatal disease which is close relative of miRNA aberrant expression and apoptosis disorders. Elucidation of the therapeutic efficacy through investigating the changes in miRNA and apoptosis holds immense importance in advancing the development of miRNA-based precision therapy. However, it remains a challenge as how to visually evaluate the efficacy during protocol optimization of miRNA-based anticancer drugs at the cellular level. Therefore, exploring effective and noninvasive methods for real-time monitoring of therapeutic efficacy in living cells is of great significance. Herein, we reported a novel fluorescent nanoprobe COF–H1/H2-Peptide for visually evaluating drug efficacy in living cells through amplified imaging of low-abundant miRNA-221 with catalytic hairpin assembly (CHA) circle amplification, as well as simultaneous caspase-3 imaging. With strong stability and good biocompatibility, this newly fabricated amplified nanoprobe showed high sensitivity and specificity for the detection of miRNA-221 and caspase-3, and the limit of detection (LOD) of miRNA-221 was as low as 2.79 pM. The fluorescent imaging results showed that this amplified nanoprobe could not only detect caspase-3 in living cells, but also effectively detect low levels of miRNA-221 with increasing anticancer drug concentration and treatment time. The smart nanoprobe had effective performance for optimizing miRNA-based drug treatment schedules by dual-color fluorescence imaging. This nanoprobe combined CHA amplified detection of intracellular miRNA-221 and synchronous apoptosis imaging, with excellent sensitivity for the detection of cellular low-level miRNA, enabling the realization of real-time assessment of the efficacy of miRNA-based therapy in living cells. This work presents a promising approach for revealing the regulatory mechanisms between miRNAs and apoptosis in cancer occurrence, development, and treatment.

中文翻译：

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使用基于 COF 的荧光纳米探针，通过 miRNA 的 CHA 放大检测和同步凋亡成像，直观地评估活细胞中的药物疗效

癌症是一种高度致命的疾病，与miRNA异常表达和细胞凋亡疾病密切相关。通过研究 miRNA 和细胞凋亡的变化来阐明治疗效果对于推进基于 miRNA 的精准治疗的发展具有重要意义。然而，如何在细胞水平上直观地评估基于 miRNA 的抗癌药物的方案优化过程中的疗效仍然是一个挑战。因此，探索有效、无创的活细胞治疗效果实时监测方法具有重要意义。在此，我们报道了一种新型荧光纳米探针 COF-H1/H2-肽，通过催化发夹组装 (CHA) 环扩增以及同时 caspase-3 对低丰度 miRNA-221 进行放大成像，直观地评估活细胞中的药物疗效成像。这种新制备的扩增纳米探针具有很强的稳定性和良好的生物相容性，对miRNA-221和caspase-3的检测表现出高灵敏度和特异性，并且miRNA-221的检测限（LOD）低至2.79 pM。荧光成像结果表明，这种放大的纳米探针不仅可以检测活细胞中的caspase-3，而且随着抗癌药物浓度和治疗时间的增加，可以有效检测低水平的miRNA-221。该智能纳米探针具有通过双色荧光成像优化基于 miRNA 的药物治疗方案的有效性能。该纳米探针结合了细胞内miRNA-221的CHA放大检测和同步凋亡成像，对细胞低水平miRNA的检测具有优异的灵敏度，能够实现活细胞中基于miRNA的治疗效果的实时评估。这项工作为揭示癌症发生、发展和治疗中 miRNA 和细胞凋亡之间的调节机制提供了一种有前景的方法。