Multivesicular vesicles (MVVs) are artificial liposomal structures widely used as a platform to study the compartmentalisation of cells and as a scaffold for artificial cell/protocell models. Current preparation techniques for MVVs, however, offer poor control on the size, lamellarity, and loading of inner lipid vesicles. Here, we introduce a microfluidic device for the production of multivesicular droplets (MVDs): a novel model system combining the ease of use and control of droplet microfluidics with the biological relevance of MVVs. We use a perfluorinated carrier phase with a biocompatible surfactant to generate monodisperse droplets of an aqueous giant unilamellar lipid vesicle suspension. The successful on-chip formation and stability of MVDs is verified through high-speed microscopy. For bright field or fluorescence microscopy inspection, the MVDs are trapped in an array where the integrity of both lipid vesicles and droplets is preserved for up to 15 minutes. Finally, we show a two-step enzymatic reaction that takes place across the lipid vesicle membranes; the second reaction step occurs in the vesicle's interior, where the enzyme is encapsulated, while both the substrate and fluorescent product permeate across the membrane. Our approach opens the possibility to mimic artificial organelles with optimised reaction parameters (pH, ions, etc.) in each compartment.

中文翻译：

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多囊泡液滴：研究隔室生化反应的细胞模型系统

多囊泡（MVV）是人工脂质体结构，广泛用作研究细胞区室化的平台和人工细胞/原始细胞模型的支架。然而，当前用于MVV的制备技术不能很好地控制内部脂质囊泡的大小，层状和负载。在这里，我们介绍了一种用于生产多囊液滴（MVD）的微流控装置：一种新颖的模型系统，将易用性和液滴微流控技术与MVV的生物学相关性相结合。我们使用具有生物相容性表面活性剂的全氟化载体相来生成水性巨单层脂质囊泡悬浮液的单分散液滴。MVD在芯片上的成功形成和稳定性已通过高速显微镜验证。对于明场或荧光显微镜检查，MVD被困在一个阵列中，其中脂质囊泡和液滴的完整性最多可保留15分钟。最后，我们显示了跨脂质囊泡膜发生的两步酶促反应。第二个反应步骤发生在囊泡的内部，在囊泡中包裹了酶，而底物和荧光产物都透过了膜。我们的方法为模拟具有最佳反应参数（pH，离子，而底物和荧光产物都渗透到整个膜上。我们的方法为模拟具有最佳反应参数（pH，离子，而底物和荧光产物都渗透到整个膜上。我们的方法为模拟具有最佳反应参数（pH，离子，等））。