Binding and Release of Reactive Oxygen Species-Responsive Charge Reversal Cationic Polymers with DNA Studied by Surface Plasmon Resonance

— We have designed and synthesized a novel cationic polymer, poly[(2-acryloyl)ethyl ( p -boronic acid)benzyl diethylammonium bromide], whose p -boronic acid benzyl can be converted to anionic poly(acrylic acid). Herein, the complexation of the cationic polymer with DNA and their disassembly triggered by reactive oxygen species were analyzed in real time by a high-resolution surface plasmon resonance. We have found that both single-stranded DNA and double-stranded DNA could bind to cationic polymer and immobilized onto the Au surface via electrostatic interactions with the binding constant 1.4 × 10 11 M –1 for double-stranded DNA and 1.0 × 10 11 M –1 for single-stranded DNA. Upon adding H 2 O 2 , the adsorbed DNA was quickly released due to cationic polymer turned into negatively charged poly(acrylic acid). Thus, this study confirmed that the polymer that can undergo positive to negative charge-reversal and provide the quick release of DNA for effective gene transfection.