Photo-driven pulsating vesicles from self-assembled lipid-like azopolymers

A unique respiring behavior of artificial cells based on self-assembled vesicles of photo-responsive azobenzene-endcapped polyethylene glycol (Azo-PEGs) was reported. The extraordinarily large change in vesicle size originates from an isomerization-driven molecular assembly upon UV-Vis irradiation cycles, and is associated with substantial transmembrane solvent transportation. The actual mechanism is believed to be complex although it is clear that the azobenzene groups act as photo-trigger which allows a large amount of water being repeatedly pumped in or out of the vesicles by visible or UV irradiation.