From adhesion to biofilms formation and resilience: Exploring the impact of silver nanoparticles-based biomaterials on Pseudomonas aeruginosa

Colonization of medical devices by microorganisms, often progressing to the formation of resilient biofilms, presents a common clinical issue. To address this challenge, there is growing interest in developing novel biomaterials with antimicrobial/antibiofilm properties as a promising preventive measure. This study explores nanocomposite biomaterials based on silver nanoparticles (AgNPs) deposited on thin silica (SiO₂) layers for their potential effect on the adhesion, detachment, viability and biofilm formation of the opportunistic Pseudomonas aeruginosa. The AgNPs-based biointerface effect on biofilm development is investigated on the PAO1-Tn7-gfp strain by combining experiments under static and dynamic conditions. For the latter, a shear-stress flow chamber is used to mimic conditions encountered around certain medical devices. The findings reveal a rapid bactericidal effect of the AgNPs, noticeable within 30 min of exposure. Moreover, a delay in surface colonization is observed with a thin and unstructured biofilm, even after 72h of dynamic culture. A considerable fragility and sensitivity to hydrodynamic stresses is noticed for this loosely attached bacterial monolayer when compared with the thick and resilient biofilm formed on SiO₂ surface. This study underlines the potential of AgNPs-based biomaterials in the conception of novel antimicrobial/antibiofilm surfaces with controlled release of the biocidal agent.