Reversible photo-switching in a cell-sized vesicle

A photosensitive amphiphilic molecule can switch the shape of an assembled vesicle as determined by microscopic observation. Photo-isomerization induces a change in membrane fluctuation behavior or a morphological transition between ellipsoid and bud shapes, depending on the asymmetrical degree of the initial shape. The mechanism of this reversible photo-switching in the vesicle morphology is interpreted in terms of a change in the effective cross-sectional area of the photosensitive molecule.