Ultrasonically synthesized Cu/Ag/Zn nanocomposite coatings for antibacterial and antibiofilm applications in urological devices

Catheter-associated urinary tract infections (CAUTIs) pose a persistent clinical challenge due to bacterial colonization and biofilm formation on indwelling urological devices. This study investigates the efficacy of Cu/Ag/Zn trimetallic nanocomposites (TMNCs) as antimicrobial coatings for urinary catheters, synthesized via a green, ultrasonic-autoclave-assisted method. The nanocomposites were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis, and field emission scanning electron microscopy (FESEM) to confirm their mesoporous, crystalline, uniformly distributed, and thermally stable nanoparticles. An optimized ultrasonic embedding technique was employed to uniformly coat TMNCs onto commercial urinary catheters, ensuring strong adhesion and consistent coverage. Antibacterial assays demonstrated concentration-dependent inhibition zones, reaching up to 21.5 mm for Escherichia coli and 24.0 mm for Staphylococcus aureus. Minimum inhibitory concentration (MIC) tests confirmed potent bactericidal activity, with MIC values of 32 µg/mL for E. coli and 64 µg/mL for S. aureus. Anti-biofilm assessments revealed that TMNCs matched or outperformed the efficacy of vancomycin, achieving up to 86.12 % inhibition for S. aureus and 73.59 % for E. coli at 2 × MIC. Cytotoxicity testing using U87 glioblastoma cells indicated good biocompatibility, with over 79 % cell viability at 0.1 mg/mL, followed by a dose-dependent decline at higher concentrations. Long-term stability studies conducted over 60 days under varied storage conditions confirmed the photothermal and colloidal stability of the TMNCs. In conclusion, Cu/Ag/Zn TMNC-coated urinary catheters demonstrated excellent antibacterial and anti-biofilm properties, biocompatibility, and long-term stability. These multi-functional coatings present a promising strategy for reducing CAUTI incidence and improving patient safety and clinical outcomes in urological applications.