Interaction between plasmid DNA and cationic polymers studied by surface plasmon resonance spectrometry

A universal and novel strategy for the immobilization of polymers has been developed for studying the interaction between plasmid DNA and synthetic po lymers with surface plasmon resonance spectrometry. The introduction of thi ol moieties in polymers has been applied for a reliable determination of ap parent kinetic rate constants between plasmid DNA and the nonviral carrier polymers. Thiolated poly(L-lysine) and poly[(2-dimethylamino)ethyl methacry late] yielded reproducible sensor surfaces, contrary to the nonthiolated po lymers. The knowledge of the kinetic parameters may play a crucial role in the development of nonviral carrier systems for gene therapy, because the d issociation rate constant is strongly correlated to the effectiveness of ce ll transfection.