Mussel-inspired surface modification of urinary catheters with both zwitterionic and bactericidal properties for effectively preventing catheter-associated infection

Catheter-associated urinary tract infections (CAUTIs), caused by rapid bacterial colonization and biofilm formation on urinary catheters (UCs), are one of the most common hospital-acquired infections. To address this challenge, introducing non-leaching contact-killing bactericidal and antifouling functions on UCs becomes an attractive way to prevent infections. However, current surface strategies for UCs still have limitations, such as the weakening bactericidal/antifouling activities due to competition between diverse components, and complex preparation procedures. Herein, we report a facile and effective surface modification strategy for commercial UC by organic integration of contact-killing and antifouling functionalities to combat biofilm formation. In this proposal, amino-rich quaternary ammonium polyethyleneimine (QPEI) was selected as a bactericidal linker to react covalently with both adhesive dopamine (DA) and antifouling component of poly(carboxylbetaine-co-dopamine methacrylamide) copolymer (pCBDA) via mussel-inspired chemistry, resulting in robust co-deposition of a hydrophilic and uniform polymeric coating (defined as QCB) onto commercial UC surface. The well-designed QCB coating endows modified surface the ability to not only efficiently resist the attachment of bacteria (bacterial antiadhesion rate: > 99.5 %), but also maintain remarkable bactericidal property of QPEI (kill efficiency: > 99.9 %), thereby preventing biofilm formation even after daily exposure to the bacteria-contacting environment over 30 days. More importantly, QCB-coated UC performed an excellent anti-infective activity in vivo using urinary tract infection rabbit models. Meanwhile, a low level of inflammatory response in vivo suggested good biocompatibility of QCB coating. It is envisioned that the QCB coating will provide a promising solution for UC to address CAUTIs.