Unexpected Interactions of an Alternating Poly(ether-ester) with Artificial and Biological Bilipidic Membranes

The anionic polymerization of a spiro monomer containing both an ester-activated cyclopropane moiety and a 1,4,7,10,13-pentaoxacyclohexadecane-14,16-dione crown ether bislactone unexpectedly yielded a linear alternating poly(ether-ester) via the ring-opening polymerization of the crown ether cycle. Ion conductivity measurements using black lipid membranes as model systems showed that oligomers of this structure are able to permeabilize bilipidic membranes, with single-ion channel behaviors being observed. Biological assays on fibroblast cells indicated a significant cytotoxicity, probably related to the above permeabilization mechanism.