miR-155是一类与癌症转移和侵袭密切相关的癌症标志物。原位检测与基因沉默相结合不仅有助于分析细胞中microRNA表达的丰度和空间位置信息，而且可以协同治疗。在这项工作中，我们利用MCF-7细胞膜制备了具有三个发夹DNA的HD@CM囊泡。发夹DNA可以被内源性miR-155触发，打开自催化分子回路（ACHA）并获得Y形DNA纳米结构。这种纳米结构不仅能够以高灵敏度原位成像检测内源性 miR-155，而且能够对细胞内生存素 mRNA 进行基因调控。通过 HD@CM 检测，MDA-MB-231、MCF-7、Hela 和 HEK-293T 细胞中 miR-155 的水平分别为 7703、3978、1696 和 1229 个拷贝/细胞。共聚焦成像发现HD@CM与不同细胞共孵育后产生的荧光与细胞内miR-155含量成正比。此外，Y形DNA结构的基因调控功能导致survivin蛋白表达显着抑制，细胞凋亡率高达83%。我们期待HD@CM平台未来应用于临床癌症的精准诊断和可编程治疗。

miR-155 is a class of cancer markers closely related to cancer metastasis and invasion. Combining in situ detection with gene silencing not only helps to analyze the information on the abundance and spatial location of microRNA expression in the cell but also synergizes the therapy. In this work, we prepared HD@CM vesicles with three hairpin DNAs by using MCF-7 cell membranes. The hairpin DNAs can be triggered by endogenous miR-155, which opens the autocatalytic molecular circuit (ACHA) and obtains Y-shaped DNA nanostructures. This nanostructure not only detects endogenous miR-155 with high sensitivity for in situ imaging but also enables gene regulation of intracellular survivin mRNA. The levels of miR-155 in MDA-MB-231, MCF-7, Hela, and HEK-293T cells are found to be 7703, 3978, 1696, and 1229 copies/cell, respectively, as detected by HD@CMs. The fluorescence produced by HD@CM after coincubation with different cells is found to be proportional to the intracellular miR-155 content by confocal imaging. In addition, the gene regulatory function of the Y-shaped DNA structure resulted in significant inhibition of survivin protein expression and apoptosis rates of up to 83%. We look forward to the future application of our HD@CM platform for the precise diagnosis and programmable treatment of clinical cancers.