School of Chemical Engineering and Translational Nanobioscience Research Center, Sungkyunkwan University, Suwon 16419, Republic of Korea.
School of Healthcare and Biomedical Engineering, Chonnam National University, Yeosu 59626, Republic of Korea.
Langmuir. 2022 Apr 19;38(15):4606-4616. doi: 10.1021/acs.langmuir.1c03384. Epub 2022 Apr 7.
Single-chain lipid amphiphiles such as fatty acids and monoglycerides along with structurally related surfactants have received significant attention as membrane-disrupting antimicrobials to inhibit bacteria and viruses. Such promise has motivated deeper exploration of how these compounds disrupt phospholipid membranes, and the membrane-mimicking, supported lipid bilayer (SLB) platform has provided a useful model system to evaluate corresponding mechanisms of action and potency levels. Even so, it remains largely unknown how biologically relevant membrane properties, such as sub-100 nm membrane curvature, might affect these membrane-disruptive interactions, especially from a nanoarchitectonics perspective. Herein, using the quartz crystal microbalance-dissipation (QCM-D) technique, we fabricated intact vesicle adlayers composed of different-size vesicles (70 or 120 nm diameter) with varying degrees of membrane curvature on a titanium oxide surface and tracked changes in vesicle adlayer properties upon adding lauric acid (LA), glycerol monolaurate (GML), or sodium dodecyl sulfate (SDS). Above their critical micelle concentration (CMC) values, LA and GML caused QCM-D measurement shifts associated with tubule- and bud-like formation, respectively, and both compounds interacted similarly with small (high curvature) and large (low curvature) vesicles. In marked contrast, SDS exhibited distinct interactions with small and large vesicles. For large vesicles, SDS caused nearly complete membrane solubilization in a CMC-independent manner, whereas SDS was largely ineffective at solubilizing small vesicles at all tested concentrations. We rationalize these experimental observations by taking into account the interplay of the headgroup properties of LA, GML, and SDS and curvature-induced membrane geometry, and our findings demonstrate that membrane curvature nanoarchitectonics can strongly influence the membrane interaction profiles of antimicrobial lipids and surfactants.
单链脂质两亲物，如脂肪酸和单甘油脂，以及结构相关的表面活性剂，作为破坏细胞膜的抗菌剂，抑制细菌和病毒，受到了极大的关注。这种前景促使人们更深入地探索这些化合物如何破坏磷脂膜，而膜模拟的、支撑的脂质双层（SLB）平台提供了一个有用的模型系统，用于评估相应的作用机制和效力水平。即便如此，对于生物相关的膜性质，如亚 100nm 的膜曲率，如何影响这些破坏细胞膜的相互作用，尤其是从纳米结构学的角度来看，仍然知之甚少。在此，我们使用石英晶体微天平耗散（QCM-D）技术，在氧化钛表面上制备了由不同大小的囊泡（70 或 120nm 直径）组成的完整囊泡层，这些囊泡具有不同程度的膜曲率，并跟踪了在添加月桂酸（LA）、甘油单月桂酸酯（GML）或十二烷基硫酸钠（SDS）时囊泡层性质的变化。在它们的临界胶束浓度（CMC）值以上，LA 和 GML 分别引起 QCM-D 测量值的变化，与管状和芽状形成有关，并且这两种化合物与小（高曲率）和大（低曲率）囊泡的相互作用相似。相比之下，SDS 与小囊泡和大囊泡表现出明显不同的相互作用。对于大囊泡，SDS 以与 CMC 无关的方式几乎完全溶解膜，而 SDS 在所有测试浓度下对小囊泡的溶解作用都很小。我们通过考虑 LA、GML 和 SDS 的头基性质和曲率诱导的膜几何形状的相互作用，解释了这些实验观察结果，我们的研究结果表明，膜曲率纳米结构学可以强烈影响抗菌脂质和表面活性剂的膜相互作用特性。
