Department of Chemistry, University of Colorado Denver, Campus Box 194, P.O. Box 173364, Denver, Colorado 80217-3364, USA.
J Phys Chem B. 2013 Feb 21;117(7):2113-22. doi: 10.1021/jp308305y. Epub 2013 Feb 6.
Simple supported lipid bilayers do not accurately reflect the complex heterogeneity of cellular membranes; however, surface modification makes it possible to tune membrane properties to better mimic biological systems. Here, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (DETAS), a silica modifier, facilitated formation of supported lipid bilayers on silica nanoparticles. Evidence for a stable supported bilayer came from the successful entrapment of a soluble fluorophore within an interstitial water layer. A fluorescence-quenching assay that utilized a pore-forming peptide was used to demonstrate the existence of two separate lipid leaflets. In this assay, fluorescence was quenched by dithionite in roughly equal proportions prior to and after addition of melittin. When a hydrophobic modifier, octadecyltriethoxysilane, was codeposited on the nanoparticles with DETAS, there was a decrease in the amount of supported bilayer on the nanoparticles and an increase in the quantity of hybrid membrane. This allowed for a controlled mixture of two distinct types of membranes on a single substrate, one separated by a water cushion and the other anchored directly on the surface, thereby providing a new mimic of cellular membranes.
简单的支撑脂质双层并不能准确反映细胞膜的复杂异质性；然而，通过表面修饰可以调节膜的性质，从而更好地模拟生物系统。在这里，3-[2-(2-氨乙基氨基)乙基氨基]丙基三甲氧基硅烷（DETAS），一种硅烷偶联剂，促进了在硅纳米粒子上形成支撑脂质双层。稳定支撑双层的证据来自于成功地将可溶性荧光团捕获在层间水层中。利用形成孔的肽的荧光猝灭测定法证明了存在两个独立的脂质双层。在该测定法中，在添加蜂毒素之前和之后，二硫苏糖醇以大致相等的比例猝灭荧光。当十八烷基三乙氧基硅烷与 DETAS 一起共沉积在纳米粒子上时，纳米粒子上的支撑双层的量减少，而混合膜的量增加。这允许在单个基底上控制两种不同类型的膜的混合物，一种通过水垫隔开，另一种直接固定在表面上，从而为细胞膜提供了新的模拟物。
