Atomic force microscopic investigations of transient early-stage bacterial adhesion and antibacterial activity of silver and ceria modified bioactive glass

Abstract

Bioactive glass 58S (BG58S) is widely recognised for its bioactivity and antibacterial properties, making it a promising material for orthopaedic implant applications. This study investigates the effects of incorporating silver (BG58S-2.5Ag) and cerium oxide (BG58S-5C) into BG58S on early-stage bacterial adhesion and subsequent bacterial growth inhibition. Using a high-intensity ball milling approach, BG58S was modified with 5% cerium oxide (CeO2) and 2.5% silver (Ag) nanoparticles to create homogeneous BG58S-2.5Ag and BG58S-5C nanocomposites. Custom-made biomineral probes were employed to measure the bacterial adhesion within one second of contact with Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, using Atomic Force Microscopy (AFM). The results demonstrated that BG58S-2.5Ag showed significantly stronger transient adhesion to bacteria compared to BG58S, leading to a more effective long-term antibacterial response. Additionally, it was observed that the antibacterial effect of Ag commenced within one second of contact. These findings indicate a potential correlation between the rate of bond strengthening and cell wall penetration. This study highlights the potential for enhancing the effectiveness of antibacterial implant surfaces for various biomaterial applications.Graphical abstract