Surface modification of urinary catheters with antibiofilm nanocoating: curcumin modified silver nanoparticles against Proteus mirabilis

Abstract

Proteus mirabilis is a Gram-negative, uropathogenic bacterium with high virulence due to its crystalline biofilm-forming ability, urease production, and antibiotic resistance. Nanotechnology has emerged as a promising field to address such challenges, offering innovative solutions to combat bacterial virulence and antibiotic resistance. This study aimed to develop a urinary catheter surface coated with curcumin-modified silver nanoparticles (Curcumin-AgNPs) to reduce crystalline biofilm formation by P.mirabilis. The coating was assessed using Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy(AFM), scanning electron microscopy-energy-dispersive X-ray analysis(SEM-EDX), and contact angle assays. The antimicrobial efficacy was examined by direct contact assay, serial plate transfer test (SPTT), and time kill assay. Coated catheters were experimented with using an in vitro bladder model over 2, 7, and 14 days, and at the point of catheter blockage. Antibiofilm efficacy was examined using tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), crystal violet(CV) assays, SEM-EDX, and atomic absorption spectroscopy(AAS) analysis. P-values < 0.05 were considered statistically significant. FTIR, AFM, SEM, and EDX analyses confirmed the successful coating of the Foley catheter with curcumin-AgNPs. A contact angle measurement of 120.11° demonstrated the hydrophobic nature of the coated catheter. The direct contact assay revealed inhibition zones for coated catheters (11.85 ± 1.86 mm). The coating demonstrated strong antibiofilm activity, with 70 - 80% biomass reduction and 60-80% metabolic inhibition even at the point of catheter blockage. AAS, SEM-EDX analysis showed reduced Ca²⁺ and Mg²⁺ deposition in coated catheters. The findings indicate that curcumin-AgNPs coatings markedly improve the antibacterial and antibiofilm efficacy of urinary catheters, successfully inhibiting crystalline biofilm formation.