The artificial manipulation of exogenous molecules in living cells is a promising means to regulate cellular behaviors. However, the spatiotemporal control of self-assembly within the complex intracellular environment remains grand challenge. Herein, we report a controlled sequential assembly of DNA nanoparticles in living cells, responding to acidic environment in lysosome, which enables lysosome interference and subsequently regulates a series of cellular behaviors. Two types of ultra-long DNA chains (DNA-chain-1 and 2) synthesized rolling circle amplification were compressed by magnesium ion to two DNA nanoparticles (DNP-1 and 2), respectively. In the acidic environment of lysosomes, both DNP-1 and DNP-2 dissociated to DNA chains, and the DNA chains were subsequently assembled through base-pairing to form a hydrogel. This sequential assembly process consumed hydrogen ions within the lysosome, decreased lysosomal acidity, and thus altered the hydrolase activity and lysosomal membrane permeability. The interference of sequential assembly on lysosomes promoted cell movement in human breast adenocarcinoma MCF-7 cells, with 81.19% and 36.24% enhancement in cell migration and invasion capacity, respectively; the level of cellular autophagy was increased by 170.00%. Our study provides a new strategy for the sequential assembly of exogenous DNA materials in living cells.

中文翻译：

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细胞内 DNA 纳米颗粒的顺序组装可实现溶酶体干扰和细胞行为调节

人工操纵活细胞中的外源分子是调节细胞行为的一种有前途的手段。然而，复杂的细胞内环境中自组装的时空控制仍然是巨大的挑战。在此，我们报道了活细胞中 DNA 纳米粒子的受控顺序组装，响应溶酶体中的酸性环境，从而实现溶酶体干扰并随后调节一系列细胞行为。滚环扩增合成的两种超长DNA链（DNA-chain-1和2）分别被镁离子压缩到两个DNA纳米颗粒（DNP-1和2）上。在溶酶体的酸性环境中，DNP-1和DNP-2均解离为DNA链，随后DNA链通过碱基配对组装形成水凝胶。这种顺序组装过程消耗了溶酶体内的氢离子，降低了溶酶体酸度，从而改变了水解酶活性和溶酶体膜通透性。顺序组装对溶酶体的干扰促进了人乳腺癌MCF-7细胞的细胞运动，细胞迁移和侵袭能力分别增强了81.19%和36.24%；细胞自噬水平增加170.00%。我们的研究为活细胞中外源 DNA 材料的顺序组装提供了一种新策略。