Askew Hannah J, Charnley Mirren, Jarvis Karyn L, McArthur Sally L
Biointerface Engineering Group, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Biointerface Engineering Group, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia and Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Biointerphases. 2017 Jun 7;12(2):02C416. doi: 10.1116/1.4984261.
Model lipid vesicle and supported lipid bilayer (SLB) systems are used in a variety of applications including biosensing, cell membrane mimics, and drug delivery. Exposure of a surface to a vesicle solution provides a straightforward method for creating such systems via vesicle adsorption and collapse. However, this process is complex and the relationship between the surface physicochemical properties and vesicle collapse is poorly understood. Plasma polymers are thin conformal films that can be applied to a variety of materials to modify surface properties. This paper uses quartz crystal microbalance with dissipation and fluorescence recovery after photobleaching (FRAP) to explore lipid vesicle interactions with plasma polymerized acrylic acid (ppAAc), allylamine (ppAAm), and ppAAc/ppAAm micropatterns. Vesicle interactions were dependent on plasma polymer chemistry and pH of the buffer solution. Vesicles readily and stably adsorbed to ppAAm over a wide pH range. ppAAc demonstrated limited interactions at pH 7 and vesicle adsorption at pH 4. Vesicle collapse and SLB formation could be induced using a pH change. FRAP was used to explore the fluidity of the lipid structures on both the patterned and unpatterned plasma polymer films. On ppAAm/ppAAc micropatterns, pH transitions combined with the presence of chemically distinct regions on the same substrate enabled immobile lipid islands on ppAAc to be surrounded by fluid lipid regions on ppAAm. This work demonstrates that plasma polymer films could enable spatially controlled vesicle adsorption and SLB formation on a wide variety of different substrates.
模型脂质囊泡和支撑脂质双层（SLB）系统被用于包括生物传感、细胞膜模拟和药物递送在内的各种应用中。将表面暴露于囊泡溶液中提供了一种通过囊泡吸附和塌陷来创建此类系统的直接方法。然而，这个过程很复杂，而且表面物理化学性质与囊泡塌陷之间的关系还不太清楚。等离子体聚合物是可以应用于各种材料以改变表面性质的薄 conformal 膜。本文使用具有耗散功能的石英晶体微天平以及光漂白后荧光恢复（FRAP）技术来探究脂质囊泡与等离子体聚合丙烯酸（ppAAc）、烯丙胺（ppAAm）以及 ppAAc/ppAAm 微图案之间的相互作用。囊泡相互作用取决于等离子体聚合物的化学性质和缓冲溶液的 pH 值。在很宽的 pH 范围内，囊泡能容易且稳定地吸附到 ppAAm 上。ppAAc 在 pH 为 7 时表现出有限的相互作用，而在 pH 为 4 时囊泡会发生吸附。可以通过改变 pH 值来诱导囊泡塌陷和 SLB 的形成。FRAP 被用于探究图案化和未图案化的等离子体聚合物薄膜上脂质结构的流动性。在 ppAAm/ppAAc 微图案上，pH 转变以及同一基底上化学性质不同区域的存在使得 ppAAc 上的固定脂质岛被 ppAAm 上的流动脂质区域所包围。这项工作表明，等离子体聚合物薄膜能够在各种不同的基底上实现空间可控的囊泡吸附和 SLB 形成。
