Novel amphiphilic cationic block copolymers by RAFT and their complexes with DNA

Abstract:  Amphiphilic cationic block copolymers present a number of interesting stimuli responsive self-assembly properties in aqueous solutions and application potential in gene delivery and antimicrobial protocols. Reversible addition-fragmentation chain transfer (RAFT) polymerization has been proven to be an effective and flexible synthesis methodology for the preparation of different block copolymer architectures using a gamut of functional monomers. Here we present the synthesis of novel diblock copolymers, random-diblock terpolymers and linear triblock terpolymers based on (2-dimethylamino) ethyl methacrylate, lauryl methacrylate and oligoethyleneglycol methacrylate monomers utilizing RAFT polymerization schemes. The copolymers present stimuli responsive self-assembly behavior in aqueous media as a function of copolymer molecular characteristics, architecture and solution pH, temperature and ionic strength. Their co-assembly with linear DNAs, in the form of electrostatic complexes, is dictated to a large extend by the copolymer architecture and copolymer/DNA ratio, as indicated by light scattering experiments and TEM observations.