Shape Formation of Liposomes and the Principle of the Least Bending Energy of Membranes

Toshio Sekimura¹ and Hirokazu Hotani²

¹College of Engineering. Chubu University, Kasugai, Aichi 487, Japan
²Department of Biophysics, Faculty of Science, Kyoto University, Kyoto 606, Japan

(Received April 28, 1989; Accepted July 3, 1989)

Keywords: Shape Formation, Liposome, Bending Energy, Lipid Bilayer

Abstract. Based on the mechanical principle of the least bending energy of membranes, we investigate the shape formation of liposomes by computer simulations and theoretical analyses. We show first that there are energetically stable liposome shapes having geometrical symmetry. We find that by reducing the volume, the stable shape can change from a circular biconcave shape as in red blood cells to elliptical, triangular, square, and higher polygonal shapes. It is also found that the preceding two results hold true irrespective of the liposome size.