School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Langmuir. 2020 May 12;36(18):5021-5029. doi: 10.1021/acs.langmuir.0c00675. Epub 2020 May 4.
Supported lipid bilayers (SLBs) are versatile cell membrane-mimicking biointerfaces for various applications such as biosensors and drug delivery systems, and there is broad interest in developing simple, cost-effective methods to achieve SLB fabrication. One promising approach involves the deposition of quasi-two-dimensional bicelle nanostructures that are composed of long-chain phospholipids and either short-chain phospholipids or detergent molecules. While a variety of long-chain phospholipids have been used to prepare bicelles for SLB fabrication applications, only two short-chain phospholipids, 1,2-dihexanoyl--glycero-3-phosphocholine and 1,2-diheptanoyl--glycero-3-phosphocholine (collectively referred to as DHPC), have been investigated. There remains an outstanding need to identify natural alternatives to DHPC, especially ones that are more affordable, to improve fabrication prospects and application opportunities. Herein, we explored the potential to fabricate SLBs from bicellar mixtures composed of long-chain phospholipids and lauric acid (LA), which is a low-cost, naturally abundant fatty acid that is widely used in soapmaking and various industrial applications. Quartz crystal microbalance-dissipation (QCM-D) experiments were conducted to track bicelle adsorption onto silica surfaces as a function of bicelle composition and lipid concentration, along with time-lapse fluorescence microscopy imaging and fluorescence recovery after photobleaching (FRAP) experiments to further characterize lipid adlayer properties. The results identified optimal conditions where it is possible to efficiently form SLBs from LA-containing bicelles at low lipid concentrations while also unraveling mechanistic insights into the bicelle-mediated SLB formation process and verifying that LA-containing bicelles are biocompatible with human cells for surface coating applications.
支持的脂质双层（SLB）是各种应用（如生物传感器和药物输送系统）中具有多功能的细胞膜模拟生物界面，人们广泛关注开发简单、经济高效的方法来实现 SLB 的制备。一种很有前途的方法涉及准二维双胶束纳米结构的沉积，该结构由长链磷脂和短链磷脂或去污剂分子组成。虽然已经使用了多种长链磷脂来制备用于 SLB 制备应用的双胶束，但只有两种短链磷脂，1,2-二己酰基-甘油-3-磷酸胆碱和 1,2-二庚酰基-甘油-3-磷酸胆碱（统称为 DHPC），已被研究过。仍然需要确定 DHPC 的天然替代品，特别是那些更经济实惠的替代品，以改善制备前景和应用机会。在此，我们探索了使用长链磷脂和月桂酸（LA）组成的双胶束混合物制备 SLB 的潜力，LA 是一种低成本、丰富的脂肪酸，广泛用于制皂和各种工业应用中。通过石英晶体微天平耗散（QCM-D）实验跟踪双胶束在二氧化硅表面的吸附作为双胶束组成和脂质浓度的函数，以及延时荧光显微镜成像和荧光恢复后光漂白（FRAP）实验，进一步研究脂质吸附层的特性。结果确定了最佳条件，可以在低脂质浓度下从含有 LA 的双胶束中有效地形成 SLB，同时还揭示了双胶束介导的 SLB 形成过程的机制见解，并验证了含有 LA 的双胶束与人细胞相容，可用于表面涂层应用。
