Investigating how vesicle size influences vesicle adsorption on titanium oxide: a competition between steric packing and shape deformation
Investigating how vesicle size influences vesicle adsorption on titanium oxide: a competition between steric packing and shape deformation
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DOI：
10.1039/c6cp07930j
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发表时间：
2017-01-21
影响因子：
3.3
通讯作者：
Cho, Nam-Joon
中科院分区：
文献类型：
--
作者：
Ferhan, Abdul Rahim;Jackman, Joshua A.;Cho, Nam-Joon
了解脂囊泡在固液界面的吸附行为对于获得软物质吸附物的基本见解以及实际应用如支撑脂质双层（SLB）制造是重要的。虽然SLB形成的过程已被高度审查，但不太了解囊泡吸附而不破裂的细节，特别是在高表面覆盖率下。在这里，我们解决这个问题，采用同步石英晶体微平衡耗散（QCM-D）和局部表面等离子体共振（LSPR）测量，以研究囊泡的大小（84-211 nm直径）的影响囊泡吸附到氧化钛表面。由于这两种技术的测量原理存在根本差异以及探测体积的不匹配，因此可以确定传感器表面附近吸附的脂质质量以及吸附的脂质和流体动力学耦合溶剂的总质量。囊泡层作为一个整体。随着囊泡大小的增加，QCM-D频率信号表现出单调的行为达到一个渐近值，而QCM-D能量耗散信号继续增加，根据囊泡的大小。与此形成鲜明对比的是，传感器表面附近的LSPR跟踪脂质质量遵循抛物线趋势，最大的相应测量响应发生在中等大小的囊泡。研究结果表明，最大程度的吸附囊泡接触固体表面发生在一个中间囊泡大小由于囊泡变形和空间包装的竞争影响。展望未来，这些信息可以应用于控制磷脂组件的分子自组装，以及为研究可变形的软物质吸附物提供基础。
Understanding the adsorption behavior of lipid vesicles at solid-liquid interfaces is important for obtaining fundamental insights into soft matter adsorbates as well as for practical applications such as supported lipid bilayer (SLB) fabrication. While the process of SLB formation has been highly scrutinized, less understood are the details of vesicle adsorption without rupture, especially at high surface coverages. Herein, we tackle this problem by employing simultaneous quartz crystal microbalance-dissipation (QCM-D) and localized surface plasmon resonance (LSPR) measurements in order to investigate the effect of vesicle size (84-211 nm diameter) on vesicle adsorption onto a titanium oxide surface. Owing to fundamental differences in the measurement principles of the two techniques as well as a mismatch in probing volumes, it was possible to determine both the lipid mass adsorbed near the sensor surface as well as the total mass of adsorbed lipid and hydrodynamically coupled solvent in the adsorbed vesicle layer as a whole. With increasing vesicle size, the QCM-D frequency signal exhibited monotonic behavior reaching an asymptotic value, whereas the QCM-D energy dissipation signal continued to increase according to the vesicle size. In marked contrast, the LSPR-tracked lipid mass near the sensor surface followed a parabolic trend, with the greatest corresponding measurement response occurring for intermediate-size vesicles. The findings reveal that the maximum extent of adsorbed vesicles contacting a solid surface occurs at an intermediate vesicle size due to the competing influences of vesicle deformation and steric packing. Looking forward, such information can be applied to control the molecular self-assembly of phospholipid assemblies as well as provide the basis for investigating deformable, soft matter adsorbates.