Nonhemolytic and Antibacterial Acrylic Copolymers with Hexamethyleneamine and Poly(ethylene glycol) Side Chains

Amphiphilic acrylic copolymers with hexamethyleneamine and poly(ethylene glycol) side chains can show u003e100-fold selectivity toward Escherichia coli over red blood cells. Homopolymer with cationic pendant amine groups is highly hemolytic and antibacterial. Incorporation of approximately 33 mol % of poly(ethylene glycol) methyl ether methacrylate (PEGMA) led to 1300 times reduction in hemolytic activity, while maintaining high levels of antibacterial activity. The hemolytic activity of these PEGylated copolymers depends on the overall content and spatial distribution of the PEGMA units. Higher activity against Escherichia coli than Staphylococcus aureus was observed for this polymer system, likely due to hydrogen bonding ability of the PEG side chains with polysaccharide cell wall of the bacteria. Field emission scanning electron microscopy analysis confirmed the bacterial membrane rupture activity exerted by these copolymers, whereas time-kill studies revealed significantly different bactericidal kinetics ...