Liposomes are versatile carriers of drugs or biomolecules and are ideally suited to transport molecules into cells. However, mechanistic studies to understand and improve the fusion of liposomes with cell membranes and endosomes are difficult. Here, we report a method that allows for stable coimmobilization of liposomes and living cells, thereby bringing the membranes into close contact, which is essential for membrane fusion. The small unilamellar liposomes are tethered to the surface by a linker so that no modification of the liposome membrane for cell binding is required. The cells are positioned above the liposomes by posts that are integrated into the microfluidic device, and a pH drop induces the fusion of the cell‐liposome membranes. Both membrane fusion and release of molecules into the cytosol are visualized by fluorescence dequenching assays. Furthermore, we proved the efficient delivery of the enzyme β‐galactosidase into the cells when a fusogenic liposome composition was used. The device could be used for fusion studies but is also a versatile means for cell transfection.

中文翻译：

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一种通过脂质体融合将酶输送到细胞中的微流体装置

脂质体是药物或生物分子的多功能载体，非常适合将分子转运到细胞中。然而，理解和改进脂质体与细胞膜和内体融合的机理研究是困难的。在这里，我们报告了一种允许脂质体和活细胞稳定共固定的方法，从而使膜紧密接触，这对于膜融合至关重要。小的单层脂质体通过接头拴在表面上，因此不需要对脂质体膜进行修饰以进行细胞结合。细胞通过集成到微流体装置中的柱子定位在脂质体上方，pH 下降会诱导细胞-脂质体膜的融合。膜融合和分子释放到胞质溶胶中都通过荧光去猝灭测定法进行可视化。此外，我们证明了当使用融合脂质体组合物时，β-半乳糖苷酶可以有效地递送到细胞中。该装置可用于融合研究，但也是一种通用的细胞转染手段。