Complex associates of plasmid DNA and a novel class of block copolymers with PEG and cationic segments as new vectors for gene delivery

Cationic block copolymers. consisting of a poly(ethylene glycol) block and a block deriving from the poly(dimethylamino)ethyl methacrylate were prepar ed via a two-step procedure, based on the use of macroinitiators. By approp riately changing the experimental conditions and reacting the poly(dimethyl amino)ethyl methacrylate block with iodo- or bromo-alkyl derivatives, a var iety of ionic block copolymers with tuned physicochemical properties were p repared. These block copolymers are able to spontaneously self-assemble wit h plasmid DNA to produce oriented and shielded vectors, with physicochemica l properties appropriate for in vivo applications. In addition, the formati on of a complex between the cationic block copolymer and the plasmid DNA re sults in a nuclease resistance increase due to the stable nature of the com plex.