Antimicrobial and hemolytic activities of copolymers with cationic and hydrophobic groups: a comparison of block and random copolymers.

Random and diblock copolymers of 2-(N,N-dimethylamino)ethyl methacrylate and butyl methacrylate are prepared by ATRP. As mimics of cationic antimicrobial peptides, the random and diblock copolymers show similar antimicrobial activities. In contrast, the diblock copolymers have much lower hemolytic activities than the random copolymers. The cell selectivity (HC(50)/MIC, where HC(50) is the concentration to lyse 50% of human red blood cells and MIC is the minimum concentration to inhibit bacterial growth) of the diblock copolymers are 150 to 27,500 times higher than that of random copolymers with similar compositions.