Kinetic evaluation of the effect of layer by layer deposition of polyelectrolytes on the stability of POPC liposomes

Layer by layer (LBL) assembly of poly(sodium 4-styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) was used to coat positively as well as negatively charged liposomes. The adsorption of either polyelectrolyte onto the liposomal surface occurs by means of electrostatic and hydrophobic interactions, depending on the structure of the polymer. The stability of the surface-modified liposomes was evaluated by monitoring the rate of the breakdown induced by the addition of increasing amounts of octaethyleneglycol mono-n-dodecylether (C12E8). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) yielded insight into the morphology of the capsules before and after the impact with the surfactant.