Lithographically defined macroscale modulation of lateral fluidity and phase separation realized via patterned nanoporous silica-supported phospholipid bilayers.
Lithographically defined macroscale modulation of lateral fluidity and phase separation realized via patterned nanoporous silica-supported phospholipid bilayers.
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通过图案化纳米多孔二氧化硅支撑的磷脂双层实现横向流动性和相分离的光刻定义宏观调控。
DOI：
10.1021/ja408434r
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发表时间：
2013
影响因子：
15
通讯作者：
Parikh,AtulN
中科院分区：
文献类型：
--
作者：
Kendall,EricL;Ngassam,VivianeN;Gilmore,SeanF;Brinker,CJeffrey;Parikh,AtulN
利用光刻技术定义的由纳米多孔和非多孔（块状）无定形二氧化硅亲水模式组成的表面，我们发现，小的单层脂质囊泡的融合产生了一个单一的、连续的、流体的双层相，经历了预定的界面相互作用模式。尽管以光漂白后荧光恢复为特征的双分子层的远程横向流动性表明名义上的单一平均扩散常数，但基于荧光显微镜的温度依赖性流动性开始测量显示，在流体-凝胶转变温度附近，纳米多孔二氧化硅支撑的双分子层区域的局部流动性增强。此外，由二元脂质混合物组成的热淬火脂质双分子层低于其明显的混溶转变温度，在支持的双分子层的每个区域诱导了质量不同的横向相分离：纳米孔衬底产生大的微观畴（和畴聚集体），而在单脂双分子层的大块玻璃支撑区域，表面纹理以小得多的畴和没有任何畴聚集体为特征。有趣的是，组成分子的横向分布也揭示了凝胶相脂质在纳米孔区域的富集，这可能是组成脂质在地形体/纳米孔边界上的不同流动性的结果。总之，这些结果表明，在双层界面施加的约束的微妙局部变化，例如粗糙度和底物粘附的空间变化，可以导致磷脂双层宏观生物物理性质的显着差异，即使在单个连续相中也是如此。
Using lithographically defined surfaces consisting of hydrophilic patterns of nanoporous and nonporous (bulk) amorphous silica, we show that fusion of small, unilamellar lipid vesicles produces a single, contiguous, fluid bilayer phase experiencing a predetermined pattern of interfacial interactions. Although long-range lateral fluidity of the bilayer, characterized by fluorescence recovery after photobleaching, indicates a nominally single average diffusion constant, fluorescence microscopy-based measurements of temperature-dependent onset of fluidity reveals a locally enhanced fluidity for bilayer regions supported on nanoporous silica in the vicinity of the fluid–gel transition temperature. Furthermore, thermally quenching lipid bilayers composed of a binary lipid mixture below its apparent miscibility transition temperature induces qualitatively different lateral phase separation in each region of the supported bilayer: The nanoporous substrate produces large, microscopic domains (and domain-aggregates), whereas surface texture characterized by much smaller domains and devoid of any domain-aggregates appears on bulk glass-supported regions of the single-lipid bilayer. Interestingly, lateral distribution of the constituent molecules also reveals an enrichment of gel-phase lipids over nanoporous regions, presumably as a consequence of differential mobilities of constituent lipids across the topographic bulk/nanoporous boundary. Together, these results reveal that subtle local variations in constraints imposed at the bilayer interface, such as by spatial variations in roughness and substrate adhesion, can give rise to significant differences in macroscale biophysical properties of phospholipid bilayers even within a single, contiguous phase.