Thermo-switchable antibacterial activity.

A copolymer system of 2-aminoethyl methacrylate and N-isopropylacrylamide comprises novel properties: changes in conformation and hydrophilicity upon heating influence the antibacterial activity and result in a switchable biocidal effect. The copolymers are characterized via NMR, MALDI-ToF MS, phase transition behavior, and antibacterial tests with E. coli or B. subtilis. MIC and MBC are determined using standard dilution methods, temperature-dependence via incubation at different temperatures and cytotoxicity by MTT tests. The copolymers exhibit lower MIC in globule than coil conformation, crosslinking on cotton results in non-leaching materials with better antibacterial activity above than below the phase-transition point.