DNA cytoskeleton for stabilizing artificial cells
DNA cytoskeleton for stabilizing artificial cells
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DOI：
10.1073/pnas.1702208114
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发表时间：
2017-07-11
影响因子：
11.1
通讯作者：
Yanagisawa, Miho
中科院分区：
文献类型：
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作者：
Kurokawa, Chikako;Fujiwara, Kei;Yanagisawa, Miho
涂覆有脂质层的细胞大小的脂质体和液滴已被用作理解活细胞、构建人工细胞以及实现功能性生物医学工具（如生物传感平台和药物递送系统）的平台。然而，这些系统非常脆弱，这是由于这些系统中没有细胞骨架。在此，我们利用DNA纳米结构构建了一种人工细胞骨架。所设计的DNA寡聚体形成Y形纳米结构，并通过其互补的粘性末端相互连接形成网络。为了用这种DNA网络对脂质膜进行底层涂覆，我们使用了吸引带负电荷DNA的阳离子脂质。通过将DNA封装到液滴中，我们成功地在膜下方创建了一个DNA壳。DNA壳增加了液滴表面的界面张力、弹性模量和剪切模量，从而稳定了脂质液滴。只有当DNA壳处于凝胶相时，才能检测到这种稳定性的显著变化。此外，我们证明了带有DNA凝胶壳的脂质体对外部渗透冲击具有相当强的耐受性。这些结果清楚地表明，DNA凝胶壳是一种类似于活细胞中细胞骨架的脂质膜稳定剂。
Cell-sized liposomes and droplets coated with lipid layers have been used as platforms for understanding live cells, constructing artificial cells, and implementing functional biomedical tools such as biosensing platforms and drug delivery systems. However, these systems are very fragile, which results from the absence of cytoskeletons in these systems. Here, we construct an artificial cytoskeleton using DNA nanostructures. The designed DNA oligomers form a Y-shaped nanostructure and connect to each other with their complementary sticky ends to form networks. To undercoat lipid membranes with this DNA network, we used cationic lipids that attract negatively charged DNA. By encapsulating the DNA into the droplets, we successfully created a DNA shell underneath the membrane. The DNA shells increased interfacial tension, elastic modulus, and shear modulus of the droplet surface, consequently stabilizing the lipid droplets. Such drastic changes in stability were detected only when the DNA shell was in the gel phase. Furthermore, we demonstrate that liposomes with the DNA gel shell are substantially tolerant against outer osmotic shock. These results clearly show the DNA gel shell is a stabilizer of the lipid membrane akin to the cytoskeleton in live cells.