Nordlund Gustav, Lönneborg Rosa, Brzezinski Peter
Department of Biochemistry and Biophysics, Centre for Biomembrane Research, Stockholm University, SE-10691 Stockholm, Sweden.
Langmuir. 2009 Apr 21;25(8):4601-6. doi: 10.1021/la8036296.
Silica colloidal particles with functionalized surfaces are used, for example, in studies of membrane proteins or for drug delivery, where novel applications are based on the use of particles covered by lipid membrane bilayers. The mechanism by which such supported lipid bilayers are formed on spherical support is not fully understood. Here, we present results from studies of this process using a new method based on flow cytometry. The approach enabled us to detect particle populations coated and uncoated with lipids in the same sample according to the vesicle:particle surface area ratio. The data suggest that DOPC lipid vesicles efficiently break upon interaction with the silica colloidal particle surface; only a small fraction of the adsorbed vesicles remain unbroken. Furthermore, the data support earlier observations showing that formation of the lipid bilayer at the surface is a cooperative process, where bilayer formation is catalyzed by previously bound membrane fragments.
表面功能化的二氧化硅胶体颗粒被用于，例如，膜蛋白研究或药物递送，其中新应用基于使用被脂质膜双层覆盖的颗粒。在球形载体上形成这种支撑脂质双层的机制尚未完全理解。在这里，我们展示了使用基于流式细胞术的新方法对该过程的研究结果。该方法使我们能够根据囊泡与颗粒的表面积比，在同一样品中检测涂有脂质和未涂有脂质的颗粒群体。数据表明，二油酰磷脂酰胆碱（DOPC）脂质囊泡在与二氧化硅胶体颗粒表面相互作用时会有效破裂；只有一小部分吸附的囊泡保持完整。此外，数据支持了早期的观察结果，表明表面脂质双层的形成是一个协同过程，其中双层的形成由先前结合的膜片段催化。
