Department of General Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, P. R. China.
Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, P. R. China.
Theranostics. 2019 Aug 14;9(20):5914-5923. doi: 10.7150/thno.36081. eCollection 2019.
DNA walker is a powerful type of DNA nanomachine that can produce amplified signals during the "burnt-bridge"-like walking process. Despite their successful application in extracellular bioanalysis, the heterogeneity of the existing DNA walkers makes it difficult to guarantee the consistency of the results during the analysis of different cells. : Here, an all-in-one homogeneous DNA walking nanomachine is reported that can be delivered into living cells for intracellular bioanalysis of miRNA without auxiliary materials. : This DNA walking nanomachine is constructed of gold nanoparticles on which two types of interrelated DNA tracks are assembled. The target miRNA, cancer-related miR-21, can be captured by one of the tracks (track 1) and then walk to the other track (track 2), releasing the hybrid of track 1 and track 2 from the nanoparticle to produce a signal. The walking process can proceed in a cyclic 1-2-1-2 manner and thereby produce amplified signals. Thus, sensitive imaging of the miRNA can be achieved. : Benefiting from the homogeneity of the detection system, the method can be applied for intracellular analysis without interference induced by the fluctuations of stimuli or accessorial contents.
DNA walker 是一种强大的 DNA 纳米机器，它可以在“烧桥”样行走过程中产生放大的信号。尽管它们在细胞外生物分析中得到了成功的应用，但现有的 DNA walker 的异质性使得难以保证在分析不同细胞时结果的一致性。在这里，报告了一种整体均相的 DNA 行走纳米机器，它可以递送到活细胞中，用于 miRNA 的细胞内生物分析，而无需辅助材料。这种 DNA 行走纳米机器是由金纳米粒子构建的，在其上组装了两种相互关联的 DNA 轨道。靶 miRNA，与癌症相关的 miR-21，可以被其中一条轨道（轨道 1）捕获，然后行走至另一条轨道（轨道 2），从而将轨道 1 和轨道 2 的杂交体从纳米粒子上释放出来以产生信号。行走过程可以以 1-2-1-2 的循环方式进行，从而产生放大的信号。因此，可以实现对 miRNA 的敏感成像。受益于检测系统的均一性，该方法可以应用于细胞内分析，而不会受到刺激或辅助内容波动引起的干扰。
