Nano-sized lipid vesicles (50–300 nm in diameter) are widely used in drug delivery systems and cosmetics. Recently, exosomes have been shown to be important as the carriers of biomolecules. The membrane structures of exosomes exhibit the same asymmetric lipid distributions as those of the plasma membranes of eukaryotic cells. The asymmetric lipid distributions of the exosome membranes play a key role in the interactions with and recognition of living cells. The asymmetric lipid distributions of nano-sized lipid vesicles facilitate delivery in advanced drug delivery systems, which emulate the cellular transportation systems of exosomes. In this study, we generate nano-sized asymmetric lipid vesicles using a pulsed-jet method for cell-sized asymmetric lipid vesicle formation. They were generated from an asymmetric planar lipid bilayer by applying pulsed-jet flows of longer duration and higher pressure than those used in the formation of micro-sized lipid vesicles. Using a transmission electron microscope, nano-sized lipid vesicles with thicknesses of approximately 5–6 nm (approximately 70 % of the generated sample), unilamellarity, and asymmetry were observed to be produced by this method. The nano-sized asymmetric lipid vesicles using this method have the potential to be useful as carriers in drug delivery systems.

纳米脂质囊泡（直径为50-300 nm）被广泛用于药物输送系统和化妆品中。近来，已显示外来体作为生物分子的载体是重要的。外泌体的膜结构表现出与真核细胞质膜相同的不对称脂质分布。外泌体膜的不对称脂质分布在与活细胞的相互作用和识别中起关键作用。纳米级脂质囊泡的不对称脂质分布有助于在先进的药物递送系统中进行递送，该系统模仿外泌体的细胞转运系统。在这项研究中，我们使用脉冲喷射方法生成纳米尺寸的不对称脂质囊泡，以形成细胞大小的不对称脂质囊泡。它们是由不对称的平面脂质双层通过施加比形成微型脂质囊泡中所使用的更长的持续时间和更高的压力的脉冲射流产生的。使用透射电子显微镜，可以观察到纳米脂质囊泡的厚度约为5–6 nm（约占所生成样品的70％），单层性和不对称性。使用该方法的纳米级不对称脂质囊泡具有用作药物递送系统中的载体的潜力。观察到通过这种方法产生了不对称性。使用该方法的纳米级不对称脂质囊泡具有用作药物递送系统中的载体的潜力。观察到通过这种方法产生了不对称性。使用该方法的纳米级不对称脂质囊泡具有用作药物递送系统中的载体的潜力。