Levy, Hernán1,2; Pezzoni, Magdalena3; Medina, Cristian2,3; Ostapchuk, Gabriel1,2,5; Villarreal, María Cristina Mina4; Violi, Ianina4; Soler-Illia, Galo J. A. A.4; Desimone, Martin F.5,6; Catalano, Paolo N.1,2,5
1 Instituto de Nanociencia y Nanotecnología (CNEA - CONICET), Nodo Constituyentes, Argentina
2 Departamento de Micro y Nanotecnología, GDTYPE, GAIDI, Centro Atómico Constituyentes, CNEA, Argentina
3 Departamento de Radiobiología, Comisión Nacional de Energía Atómica, Argentina
4 Instituto de Nanosistemas, Universidad Nacional de San Martín, Argentina
5 Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Químicas, Argentina
6 CONICET - Universidad de Buenos Aires, Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), Argentina
Jue 4/6 · 17:30–19:00
Sesión de pósters 2
Implant-associated infections, driven by biofilm formation at the nano-biointerface, remain a critical challenge. Mesoporous oxide coatings offer a unique platform to engineer surface properties at the nanoscale, enabling control over bacterial adhesion and viability.1 However, the interplay between nanotopography and ion-mediated antibacterial activity is not fully understood.
Here, we report the design of mesoporous zirconia:ceria (70:30) thin films as functional coatings with tunable antibacterial responses. Films were synthesized by sol–gel and evaporation-induced self-assembly using Pluronic F-127 and deposited by dip-coating on glass slides.2 Structural integrity and mesoporosity were confirmed by SEM. Post-synthesis infiltration with silver (Ag+), cerium (Ce3+), and zinc (Zn2+) ions was performed by incubation with the corresponding with salt solutions and analyzed by EDS. Antibiofilm formation and bactericidal activity were evaluated against Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa under nutrient-rich and physiological conditions, allowing the decoupling of biofilm inhibition and contact-killing mechanisms.
Robust crack-free mesoporous coatings were consistently obtained. EDS demonstrated Ag and Zn infiltration in films (%At fractions: Ag:Zr=1.0+0.9; Zn:Zr=0.2+0.1). Even though quantification of Ce infiltration was complex due to the presence of Ce in the mesoporous matrix, films infiltrated with these ions revealed distinctive antimicrobial activity compared to non-infiltrated mesoporous Zr-Ce coatings. Notably, Ag- and Ce-infiltrated films showed marked antibiofilm reduction. Specifically, Ag-infiltrated films achieved total reduction for P. aeruginosa and S. epidermidis, and a significant reduction for S. aureus (p < 0.005), while Ce-infiltrated coatings exhibited significant reduction (p < 0.05) across all strains. Furthermore, Ag- and Zn-infiltrated films demonstrated enhanced bactericidal effects under direct contact, where no viable bacteria were detected post-exposure. For Ce, a significant bactericidal reduction (p < 0.005) was observed for all strains. These results reveal distinct, ion-dependent mechanisms that vary between biofilm prevention and direct killing.
This work demonstrates that antibacterial responses can be rationally tuned through ion infiltration of the mesoporous architecture, providing a framework for the design of antibacterial nanoengineered surfaces with tunable biological respo