Local Membrane Mechanics of Pore-Spanning Bilayers
Local Membrane Mechanics of Pore-Spanning Bilayers
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DOI：
10.1021/ja809165h
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发表时间：
2009-05-27
影响因子：
15
通讯作者：
Janshoff, Andreas
中科院分区：
文献类型：
--
作者：
Mey, Ingo;Stephan, Milena;Janshoff, Andreas
脂质双层的机械行为，跨越高度有序的多孔硅基板的孔进行了详细检查，通过局部压痕实验作为表面功能化，脂质组合物，溶剂含量，压痕速度和孔半径的函数。含溶剂的纳米黑色脂质膜（纳米BLM）以及无溶剂的跨孔双层成像的荧光和原子力显微镜之前的力曲线采集，这使得膜覆盖和未覆盖的孔之间的区别。力压痕曲线上的跨孔双层连接到功能化的疏水多孔硅基板揭示了一个主要的线性响应，这主要是由于在膜中的预应力。这与压痕导致膜溶解远低于5%面积扩张的观察结果一致。然而，膜弯曲和横向张力占主导地位的预应力和拉伸，如果无溶剂的支撑膜从分散在亲水性多孔硅上的巨脂质体缩进。一个弹性制度图，容易允许确定的主要贡献的机械响应后，压痕作为负载和孔隙半径的函数。
The mechanical behavior of lipid bilayers; spanning the pores of highly ordered porous silicon substrates was scrutinized by local indentation experiments as a function of surface functionalization, lipid composition, solvent content, indentation velocity, and pore radius. Solvent-containing nano black lipid membranes (nano-BLMs) as well as solvent-free pore-spanning bilayers were imaged by fluorescence and atomic force microscopy prior to force curve acquisition, which allows distinguishing between membrane-covered and uncovered pores. Force indentation curves on pore-spanning bilayers attached to functionalized hydrophobic porous silicon substrates reveal a predominately linear response that is mainly attributed to prestress in the membranes. This is in agreement with the observation that indentation leads to membrane lysis well below 5% area dilatation. However, membrane bending and lateral tension dominate over prestress and stretching if solvent-free supported membranes obtained from spreading giant liposomes on hydrophilic porous silicon are indented. An elastic regime diagram is presented that readily allows determining the dominant contribution to the mechanical response upon indentation as a function of load and pore radius.