Membrane Nanotubes Increase the Robustness of Giant Vesicles
Membrane Nanotubes Increase the Robustness of Giant Vesicles
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DOI：
10.1021/acsnano.8b00640
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发表时间：
2018-05-01
期刊：
影响因子：
17.1
通讯作者：
Lipowsky, Reinhard
中科院分区：
文献类型：
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作者：
Bhatia, Tripta;Agudo-Canalejo, Jaime;Lipowsky, Reinhard
巨单层囊泡（GUV）提供了纳米和微米之间的直接联系。一方面，这些囊泡代表具有许多微米的线性尺寸的仿生隔室。另一方面，囊泡壁由具有几纳米厚度的单分子双层提供，并且对与小溶质、生物聚合物和纳米颗粒的分子相互作用敏感地响应。这些纳米级响应被GUV放大，然后可以在更大的尺度上进行研究。因此，GUV越来越多地用作基础膜科学、生物工程和合成生物学的多功能研究工具。然而，常规GUV具有一个主要缺点：它们仅具有有限的能力来科普外部扰动，例如渗透膨胀、粘附或倾向于使膜破裂的微量移液管抽吸。相比之下，细胞膜耐受相同种类的机械扰动而不破裂，因为后者膜与膜面积的储库耦合。在这里，我们介绍GUV膜纳米管作为模型系统，包括这样的面积水库。为了证明这些管状囊泡的鲁棒性增加，我们使用微量吸液管抽吸和渗透条件的变化应用于掺杂糖脂GM 1的磷脂膜。理论和实验之间的定量比较表明，GUV的响应是由膜的自发张力，曲率弹性材料参数，描述了纳米尺度上的双层不对称性。由于其增强的鲁棒性，具有纳米管的GUV代表了膜科学的改进的研究工具，通常具有作为储存和递送系统以及作为生物工程、药理学和合成生物学中的细胞样微室的潜在应用。
Giant unilamellar vesicles (GUVs) provide a direct connection between the nano- and the microregime. On the one hand, these vesicles represent biomimetic compartments with linear dimensions of many micrometers. On the other hand, the vesicle walls are provided by single molecular bilayers that have a thickness of a few nanometers and respond sensitively to molecular interactions with small solutes, biopolymers, and nanoparticles. These nanoscopic responses are amplified by the GUVs and can then be studied on much larger scales. Therefore, GUVs are increasingly used as a versatile research tool for basic membrane science, bioengineering, and synthetic biology. Conventional GUVs have one major drawback, however: they have only a limited capability to cope with external perturbations such as osmotic inflation, adhesion, or micropipette aspiration that tend to rupture the membranes. In contrast, cell membranes tolerate the same kinds of mechanical perturbations without rupture because the latter membranes are coupled to reservoirs of membrane area. Here, we introduce GUVs with membrane nanotubes as model systems that include such area reservoirs. To demonstrate the increased robustness of these tubulated vesicles, we use micropipette aspiration and changes in the osmotic conditions applied to phospholipid membranes doped with the glycolipid GM1. A quantitative comparison between theory and experiment reveals that the response of the GUVs is governed by the membranes' spontaneous tension, a curvature-elastic material parameter that describes the bilayer asymmetry on the nanoscale. Because of their increased robustness, GUVs with nanotubes represent improved research tools for membrane science, in general, with potential applications as storage and delivery systems and as cell-like microcompartments in bioengineering, pharmacology, and synthetic biology.