Automatic generation system of cell-sized liposomes

Artificial cell membranes such as liposomes and lipid vesicles have been developed using microfluidic technologies. These technologies have advantages for generating cell-sized liposomes, including a monodispersed and asymmetric lipid composition. Cell-sized asymmetric liposomes with various combinations of asymmetric lipid leaflets are sequentially produced using an improved pulsed-jetting device with the six wells arranged on a circular rotation table by manual manipulation. In this study, we reveal optimal parameters of rotation speed and jetting timing for the cell-sized liposome formation using an automatic sequential liposome generation system driven by a stepping motor. First, we optimize the rotation speed of the stepping motor for forming the planar lipid bilayer under control of a microcomputer. Next, we generate cell-sized liposomes using this automated system at the optimized rotation speed. This automatic system will contribute to high-throughput investigations of membrane protein activities and functions using the electrophysiological or the asymmetric liposome analyses.