Lipid vesicles, in particular Giant Unilamellar Vesicles (GUVs), have been increasingly
important as compartments of artificial cells to reconstruct living cell-like systems in a
bottom-up fashion. Here, we report shape transformations of lipid vesicles induced by
polyethylene glycol-lipid conjugate (PEG lipids). Statistical analysis of deformed vesicle
shapes revealed that shapes vesicles tend to deform into depended on the concentration
of the PEG lipids. When compared with theoretically simulated vesicle shapes, those
shapes were found to be more energetically favorable, with lower membrane bending
energies than other shapes. This result suggests that the vesicle shape transformations
can be controlled by externally added membrane molecules, which can serve as a
potential method to control the replications of artificial cells
