Deshpande Siddharth, Birnie Anthony, Dekker Cees
Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Biomicrofluidics. 2017 May 8;11(3):034106. doi: 10.1063/1.4983174. eCollection 2017 May.
Due to their cell membrane-mimicking properties, liposomes have served as a versatile research tool in science, from membrane biophysics and drug delivery systems to bottom-up synthetic cells. We recently reported a novel microfluidic method, Octanol-assisted Liposome Assembly (OLA), to form cell-sized, monodisperse, unilamellar liposomes with excellent encapsulation efficiency. Although OLA provides crucial advantages over alternative methods, it suffers from the presence of 1-octanol droplets, an inevitable by-product of the production process. These droplets can adversely affect the system regarding liposome stability, channel clogging, and imaging quality. In this paper, we report a density-based technique to separate the liposomes from droplets, integrated on the same chip. We show that this method can yield highly pure (>95%) liposome samples. We also present data showing that a variety of other separation techniques (based on size or relative permittivity) were unsuccessful. Our density-based separation approach favourably decouples the production and separation module, thus allowing freshly prepared liposomes to be used for downstream on-chip experimentation. This simple separation technique will make OLA a more versatile and widely applicable tool.
由于具有模拟细胞膜的特性，脂质体在科学领域已成为一种多功能的研究工具，涵盖从膜生物物理学到药物递送系统以及自下而上合成细胞等多个方面。我们最近报道了一种新型微流控方法，即辛醇辅助脂质体组装（OLA），用于形成细胞大小、单分散、单层的脂质体，且具有出色的包封效率。尽管OLA相较于其他方法具有关键优势，但它存在辛醇液滴这一生产过程中不可避免的副产物。这些液滴会在脂质体稳定性、通道堵塞和成像质量等方面对系统产生不利影响。在本文中，我们报道了一种基于密度的技术，用于在同一芯片上分离脂质体与液滴。我们表明该方法能够产生高纯度（>95%）的脂质体样品。我们还展示了数据，表明多种其他分离技术（基于尺寸或相对介电常数）均未成功。我们基于密度的分离方法有利地将生产和分离模块解耦，从而使新制备的脂质体可用于下游的芯片实验。这种简单的分离技术将使OLA成为一种更具多功能性且应用更广泛的工具。
