Spontaneous Alternating Copolymer Vesicles of Alkylmaleimides and Vinyl Gluconamide

Alternating copolymers of N-n-alkylmaleimides and vinyl gluconamide spontaneously form ultrasmall- and medium-sized (10-20 and 50-300 nm, respectively) vesicles when dissolved in water at room temperature. These materials have molecular weights that are approximately 100 times higher than those of previously reported alternating oligomers of alkylmaleate and vinyl ether monomers and conclusively demonstrate that alternating copolymers can form vesicles. The size and shape of the vesicles are thoroughly characterized by cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The copolymer vesicles exhibit alkyl-chain-length-dependent release characteristics and bilayer thickness (1.7, 2.0, and 2.6 nm for alkyl chains of 10, 12, and 14 carbons, respectively).