Controllable movement of the azobenzene linked crown ether conjugated liposome

This paper is a report on our research efforts to polymerize encapsulated actin within the liposome for embodiment of a micro sized robot that mimics locomotion of an amoeba. We employed an electroporation technique to control polymerization in a liposome. In order to optimize polymerization and depolymerization in the liposome, we compared the time of polymerization and depolymerization with various concentration of crown ether. For that purpose, we synthesized the liposome which contained the azobenzene linked crown ether conjugated actin protein since azobenzene linked crown ether held the K⁺ ion by exposure of UV light. This exposure disturbed actin polymerization. As a result, the growth and degeneration of the liposome could be controlled by external stimuli which were UV light. Therefore, we could confirm the strategy is feasible to develop an amoeba-like micro robot based on control of a liposome. The major merit of the control by UV light was that we did not need to inject proteins which then induced polymerization and depolymerization of the actin protein.