Daunomycin triggers membrane blebbing and breakage of giant DNA encapsulated in a cell-sized liposome

We studied the effect of daunomycin, a cancer chemotherapeutic agent, on a model cellular system in which folded compact DNA was encapsulated inside a cell-sized phospholipid liposome. Real-time observation with fluorescence microscopy revealed that, upon the addition of daunomycin, entrapped DNA was first elongated and then cut into fragments. A blebbing transition of the membrane was also observed. A theoretical model is proposed to explain the blebbing phenomenon induced by daunomycin, taking into account its effect on the asymmetry between the outer and inner layers of the membrane.