Peptidomimetic Polyurethanes Inhibit Bacterial Biofilm Formation and Disrupt Surface Established Biofilms

Over 80% of all chronic bacterial infections in humans are associated with biofilms, which are surface-associated bacterial communities encased within a secreted exopolysaccharide matrix that can provide resistance to environmental and chemical insults. Biofilm formation triggers broad adaptive changes in the bacteria, allowing them to be almost 1000-fold more resistant to conventional antibiotic treatments and host immune responses. The failure of antibiotics to eliminate biofilms leads to persistent chronic infections and can promote the development of antibiotic-resistant strains. Therefore, there is an urgent need to develop agents that effectively prevent biofilm formation and eradicate established biofilms. Herein, we present water-soluble synthetic peptidomimetic polyurethanes that can disrupt surface established biofilms of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, all of which show tolerance to the conventional antibiotics polymyxin B and ciprofloxacin. Furthermore, while these polyurethanes show poor antimicrobial activity against planktonic bacteria, they prevent surface attachment and stimulate bacterial surface motility to inhibit biofilm formation of both Gram-positive and Gram-negative bacteria at subinhibitory concentrations, without being toxic to mammalian cells. Our results show that these polyurethanes show promise as a platform for the development of therapeutics that target biofilms and modulate surface interactions of bacteria for the treatment of chronic biofilm-associated infections and as antibiofilm agents.