Polydopamine-Antibiotic Composite Coating for Antibiofilm Applications.

Urinary catheterization is a common procedure, affecting 15%-25% of hospitalized patients. This procedure, however, often results in bacterial infections, primarily caused by biofilm-forming Gram-negative bacteria that adhere to the catheter surface. To address this challenge, we developed a polymer-based antimicrobial coating using polydopamine (PD) embedded with gentamicin (Gent). We evaluated the antibiofilm efficacy of this coating (PD-Gent) using a biofilm-forming isolate of Pseudomonas aeruginosa (PAO1) as P. aeruginosa is commonly implicated in catheter-related infections. We observed that the PD-Gent coating significantly reduced biofilm formed by PAO1 compared to the uncoated control. Importantly, the coating maintained its antibiofilm activity across diverse substrates, including polystyrene, poly(vinyl chloride), and silicone. The approach was further extended to incorporate other antibiotics (tobramycin, amikacin), demonstrating adaptability to multiple antimicrobial agents. Finally, artificial urine inoculated with PAO1 was deployed through PD-Gent-coated silicone Foley catheters under continuous flow for 24 h. Despite this continuous introduction of PAO1, the coated catheters inhibited biofilm formation by three-fold compared to the uncoated control catheters. These findings underscore the promise of PD-Gent as a robust, versatile coating with strong potential to significantly reduce the incidence of catheter-associated infections in clinical settings.