Enhanced Antibiofilm Activity of Copper Nanoparticles Stabilized With Polyvinyl Pyrrolidone and Polyvinyl Alcohol Against <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>

Pseudomonas aeruginosa and Staphylococcus aureus are biofilm-forming pathogens that contribute to persistent infections and exhibit high resistance to conventional antibiotics. In the present study, copper nanoparticles (Cu-NPs) were synthesized using polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) as polymeric stabilizing agents to evaluate their potential in biofilm inhibition. The synthesized Cu-NPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier-Transform Infrared (FT-IR) spectroscopy, Dynamic Light Scattering (DLS), zeta potential, Field Emission Scanning Electron Microscopy (FE-SEM), Energy-Dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The average particle sizes of the two formulations were found to be ~114 nm (PVP-Cu-NP) and ~127 nm (PVA-Cu-NP). Both NPs have demonstrated strong biofilm inhibitory activity at sub-minimum inhibitory concentrations (Sub-MICs) up till Day 3. The inhibitory efficacy of PVP-NP and PVA-NP against P. aeruginosa biofilm was 59.4% and 73.10%, respectively. Whereas the inhibitory efficacy of the two formulations against S. aureus biofilm was found to be 78.94% by PVP-NP and 88.94% by PVA-NP. Additionally, the Sub-MIC concentrations of PVP-NP and PVA-NP significantly reduced cell surface hydrophobicity (CSH) and exopolysaccharide (EPS) production, thereby disrupting key components of biofilm architecture. These findings suggest that polymer-stabilized copper nanoparticles may provide promising therapeutic strategies for the prevention and control of biofilm-forming and antibiotic-resistant disease-causing pathogens.