The Optimization of the Synthesis of Antibacterial Coatings on Ti6Al4V Coupons Obtained by Electron Beam Melting

Abstract

Prosthetic joint infection represents a problem that worsens the patient’s quality of life and produces an economic impact on health systems. We report the anodization of Ti6Al4V coupons obtained by electron beam melting to produce a nanostructured surface. Anodization at 10 V produced TiO2 nanopores with a diameter in the range of 15–20 nm. Thereafter, Ag nanoparticles (AgNPs) were deposited in three different ways to provide antibacterial functionality to the coatings: electrochemically, thermally, and chemically. The electrochemical method did not provide good coverage of AgNPs. At 0.1 V of synthesis potential, cubic, octahedral, and truncated octahedral Ag crystals were obtained. The thermal method provided a good distribution of AgNPs but it damaged the TiO2 nanostructure. The chemical method showed the best distribution of AgNPs over the anodized surface and preserved the anodized nanostructure. For this reason, the chemical method was selected to perform further studies. Ag+ release was monitored in simulated body fluid at 37 °C, reaching 1.86 mg Ag+/L after 42 days. The antibacterial coating showed excellent antibacterial activity and inhibited biofilm formation for Staphylococcus epidermidis RP62A and Staphylococcus aureus V329 strains (lethality > 99.9% for both bacteria and assays).

Keywords

• antibacterial coating
• silver ion
• additive manufacturing
• electron beam melting
• Ti6Al4V