Molecular weight of polyanion affects the biological activity of interpolycomplexes

Cationic poly(diallyldimethylammonium chloride) forms nonstoichiometric positively charged interpolyelectrolyte complexes (IPECs) with short- and long-chain anionic sodium polyacrylate. When added to anionic liposomes, the short-chain polyanion IPECs dissociate and the free polycation binds to the liposomes, whereas the long-chain polyanion IPECs bind to the liposomes as a whole. These results correlate with the antimicrobial activity of IPECs, thereby highlighting the important role of polymer molecular weight in the cellular response to IPEC binding.