Fabrication of silver-containing antibacterial coating on titanium by alkaline-heat treatment and hydrothermal sterilization

Abstract

In this study, a silver-modified layer was prepared on pure titanium through alkaline-heat treatment followed by hydrothermal sterilization in diluted silver nitrate (AgNO3) solutions at 121 °C for 20 min. The effects of the AgNO3 concentration on the surface silver content, silver-containing particle distribution, and silver chemical state were investigated; the antibacterial properties of the surface-modified titanium samples against Staphylococcus aureus and their compatibility with MC3T3-E1 osteoblast-like cells were preliminarily evaluated. The results showed that the 3D network nanostructure constructed by alkaline-heat treatment on the pure titanium served as a matrix for the reduction of Ag+ ions to silver nanoparticles (AgNPs) during the hydrothermal sterilization process without the addition of a reducing agent. These AgNPs evenly distributed without aggregation, and as the AgNO3 concentration decreased from 10−2 mol/L to 10−6 mol/L, the number of AgNPs gradually decreased, but their size slightly changed. Silver-loaded surfaces exhibited good antibacterial and anti-adhesion properties. However, when the AgNO3 concentration was greater than 10−4 mol/L, the number of AgNPs on the surface was excessive, resulting in significant cytotoxicity. When the AgNO3 concentration was between 10−5 and 10−6 mol/L, good antibacterial activity and good cell compatibility were achieved synchronously.

Keywords

• Titanium
• Silver
• Antibacterial property
• Cell compatibility