Spontaneous Formation of a Vesicle Multilayer on Top of an Exponentially Growing Polyelectrolyte Multilayer Mediated by Diffusing Poly-l-lysine

We observed the spontaneous formation of vesicle-multilayers on top of a polyelectrolyte multilayer (PEM). By varying the thickness of underlying PEM (uPEM) it was possible to tailor the amount of adsorbing liposomes. Thereby, the loading capacity could be increased up to 17 times with respect to a monolayer of vesicles for an uPEM of 50.5 bilayers. We, furthermore, proved that the formation of the vesicle multilayer is due to the ability of poly-l-lysine to diffuse within the uPEM. This method could be interesting for applications in sensors and drug delivery systems where the increase in loading capacity is highly desired.