Myelin-like protrusions of giant phospholipid vesicles prepared by electroformation

Quasistable shapes of phospholipid bilayer vesicles obtained by formation in an alternating electric field [M.I. Angelova, S. Soleau, Ph. Méléard, J.F. Faucon, P. Bothorel, Prog. Colloid Polym. Sci. 89 (1992) 127; V. Heinrich, R.E. Waugh, Ann. Biomed. Eng. 24 (1996) 595] are observed. The vesicles appearing as composed of a mother sphere and a thin tubular myelin-like protrusion, are found to be a common phase in the spontaneous slow shape transformation that yields giant fluctuating phospholipid vesicles of different shapes. In the shape transformation, the myelin-like protrusion, which acts as a reservoir for the membrane area, is integrated into the mother vesicle.