Department of Chemistry, School of Chemistry and Bioengineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, P. R. China.
Nanoscale Horiz. 2019 Mar 1;4(2):472-479. doi: 10.1039/c8nh00330k. Epub 2018 Nov 21.
Intracellular microRNA (miRNA) imaging remains a key challenge due to its low abundance. Herein, we integrate a rationally designed elegant entropy-driven DNA probe with assisted DNA fuel on hollow copper sulfide nanoparticles (HCuSNPs) for intracellular miRNA imaging. The anchored assisted DNA fuel strand could be efficiently released by a NIR-II laser irradiation induced photothermal effect of the HCuSNPs. The DNA machine was activated by target miRNA binding and powered by NIR-responsive released DNA fuel through toehold-mediated strand displacement reactions, accomplished by strong fluorescence recovery. It demonstrated 2 orders of magnitude improvement in the detection sensitivity compared to molecular beacons (MBs). Reliable intracellular low-abundance miRNA imaging among different cells and monitoring of down-regulated miRNA was realized without external enzyme or fuel addition. Oncogenic miRNA imaging in vivo was also realized. The entropy-driven DNA machine system provides a facile and powerful tool for intracellular miRNA analysis and related biomedical applications.
由于其丰度低，细胞内 microRNA（miRNA）成像仍然是一个关键挑战。在此，我们将合理设计的优雅熵驱动 DNA 探针与辅助 DNA 燃料整合到中空硫化铜纳米颗粒（HCuSNPs）上，用于细胞内 miRNA 成像。锚定的辅助 DNA 燃料链可以通过 HCuSNPs 的近红外-II 激光照射诱导的光热效应有效地释放。DNA 机器通过与靶 miRNA 的结合被激活，并通过近红外响应释放的 DNA 燃料提供动力，通过引发链置换反应，实现强荧光恢复。与分子信标 (MBs) 相比，检测灵敏度提高了 2 个数量级。无需外加酶或燃料添加，即可在不同细胞中实现可靠的细胞内低丰度 miRNA 成像和下调 miRNA 的监测。体内致癌 miRNA 成像也得以实现。熵驱动的 DNA 机器系统为细胞内 miRNA 分析和相关生物医学应用提供了一种简单而强大的工具。
