SPONTANEOUS EXPULSION OF GIANT LIPID VESICLES INDUCED BY LASER TWEEZERS

Irradiation of a giant unilamellar lipid bilayer vesicle with a focuse d laser spot leads to a tense pressurized state which persists indefin itely after laser shutoff. If the vesicle contains another object it c an then be gently and continuously expelled from the tense outer vesic le. Remarkably, he inner object can be almost as large as the parent v esicle; its volume is replaced during the exit process. We offer a qua litative theoretical model to explain these and related phenomena. The main hypothesis is that the laser trap pulls in lipid and ejects it i n the form of submicron objects, whose osmatic activity then drives th e expulsion.