Tailoring of antibacterial Ag nanostructures on TiO₂ nanotube layers by magnetron sputtering

Abstract

To reduce the incidence of postsurgical bacterial infection that may cause implantation failure at the implant-bone interface, surface treatment of titanium implants with antibiotic materials such as silver (Ag) has been proposed. The purpose of this work was to create TiO2 nanotubes using plasma electrolytic oxidation (PEO), followed by formation of an antibacterial Ag nanostructure coating on the TiO2 nanotube layer using a magnetron sputtering system. PEO was performed on commercially pure Ti sheets. The Ag nanostructure was added onto the resulting TiO2 nanotube using magnetron sputtering at varying deposition rates. Field emission scanning electron microscopy and transmission electron microscopy were used to characterize the surface, and Ag content on the TiO2 nanotube layer was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning probe microscopy for surface roughness and contact angle measurement were used to indirectly confirm enhanced TiO2 nanotube hydrophilicity. Antibacterial activity of Ag ions in solution was determined by inductively coupled plasma mass spectrometry and antibacterial testing against Staphylococcus aureus (S. aureus). In vitro, TiO2 nanotubes coated with sputtered Ag resulted in significantly reduced S. aureus. Cell viability assays showed no toxicity for the lowest sputtering time group in the osteoblastic cell line MC3T3-E1. These results suggest that a multinanostructured layer with a biocompatible TiO2 nanotube and antimicrobial Ag coating is a promising biomaterial that can be tailored with magnetron sputtering for optimal performance.

Cellular Attachment and Differentiation on Titania Nanotubes Exposed to Air- or Nitrogen-Based Non-Thermal Atmospheric Pressure Plasma

“…Hence, the results of reduced cell attachment for untreated TiO 2 nanotube surfaces in our study may have been affected by EO gas sterilization. However, our previous studies with same method of sterilization, EO gas [24], [25], showed that there was no indication of compromised cellular attachment on the sterilized samples. Therefore, the effects seen here likely are not due solely to the method of sterilization used.…”

“…All the specimens were sterilized using ethylene oxide (EO) gas at a temperature of 55°C for 1 h before each experiment. EO gas sterilization was chosen for sterilization of TiO 2 nanotubes in the cell experiments because previous experiments we have verified that it has no effect on cell health [24], [25].…”

Reactive combinatorial synthesis and characterization of a gradient Ag–Ti oxide thin film with antibacterial properties

“…This can be done by tailoring topography on the nanoscale [12,35,36], by incorporating varied amounts of Ag in similar structures [13,16,37,38], or by pursuing alternative strategies for antibacterial surfaces, thoroughly surveyed in recent reviews [10,[14][15][16]22]. Although history has proven that with persistence and some chance, great discoveries can be made, the possibility of this occurring will undoubtedly be greater if more parameters can be screened in a faster and cheaper way [17,18,[39][40][41][42].…”

Controlled release of drugs in electrosprayed nanoparticles for bone tissue engineering

“…TiO 2 nanotube implants for bone interface were surface treated with silver to act as an antibiotic material and prevent any bacterial infection during postsurgical periods [80]. Synthetic polymers such as polyacrylates, polyglycolides and polycaprolactone copolymers dominate over natural polymers like collagen and gelatin; based on their capability to attain a sustained release of therapeutic agents.…”