Mitigating Pseudomonas aeruginosa biofilm formation using self-assembled bactericidal polymer coatings

Bacterial biofilms complicate the treatment of infections by enabling chronic colonization and antibiotic resistance. Infections that arise from contamination of surgical tools, medical implants, and catheters may be mitigated using antibacterial polymer coatings. Here, we describe a self-assembled polymer coating that consists of two bottlebrush copolymers which are synthesized through ring-opening metathesis polymerization. The formation of the polymer coating occurred via reversible host-guest interactions between adamantane and β-cyclodextrin and was shown to be stable on surfaces over several days in static salt solutions. Under dynamic flow conditions, the polymer coating efficiently prevented biofilm formation through a non-contact-active delamination process, even after 96 h of exposure. Moreover, bactericidal properties were demonstrated through the slow release of an antibiotic drug combination that was electrostatically loaded onto the positively charged oligoviologen side chains of the polymers. Growth inhibition was observed for up to 48 h under static conditions for the drug-loaded coatings. These results demonstrate a novel self-assembled polymer coating that was designed to possess both antifouling and bactericidal functionality under dynamic flow conditions, thus representing a novel platform with the potential to mitigate the growth of multi-drug-resistant bacteria and biofilm formation on the surface of a wide range of medical devices using nearly any combination of negatively charged antibiotics.