Antibacterial activity of a porous silver doped TiO2 coating on titanium substrates synthesized by plasma electrolytic oxidation

Abstract

The objective of this study was the development of Ag-rich antibacterial coatings on titanium (Ti) to prevent post-operative infections. A series of Ag-doped TiO2 coatings were synthesized on Ti discs by plasma electrolytic oxidation (PEO) in an electrolyte containing Ag nanoparticles (AgNPs). The incorporation, distribution and chemical composition of the AgNPs on Ti were determined using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The crystalline structure and wettability of the coating was characterized by X-ray diffraction (XRD) and water contact angle (WCA) analysis respectively. Surface roughness and hardness of the coating were examined using atomic force microscopy (AFM) and Knoop indentation test respectively, while silver ion release was quantified using inductively coupled plasma-mass spectroscopy (ICP-MS).Following PEO, the surface of the Ti substrate was converted to TiO2 composed of anatase and rutile phases. The SEM micrographs showed that the AgNPs were distributed throughout the oxide layer, without changing the morphology of the coating. The coatings also revealed an increased surface roughness, enhanced surface microhardness and improved surface wettability relative to untreated Ti substrates. Furthermore, the incorporation of Ag into the coating did not alter the phase component, surface roughness, microhardness and wettability. A series of in-vitro antibacterial assays indicated that increasing the number of AgNPs in the electrolyte led to excellent antibacterial activities, resulting in a complete reduction of Escherichia coli and a 6-log reduction of Staphylococcus aureus after 24 hours of incubation.

Surface functionalization of 3D printed structures: Aesthetic and antibiofouling properties

“…In the TiN film, the Ra was equals to 13.2 nm and WCA was equal to 28.3°, but with the silver incorporation (8.6 at.%), the roughness and WCA changed to 15.1 nm and 16.6°respectively. Other study case was performed by Thukkaram et al [55] which fabricated Ag-doped TiO 2 in order to obtain antibacterial properties. They revealed that with the silver incorporation into the films, Ra and WCA has shown opponent behaviour.…”

Hydrothermally Assisted Fabrication of TiO2-Fe3O4 Composite Materials and Their Antibacterial Activity

“…Bacterial infections may appear in postoperative wounds if the procedure for the sterilization of the instruments and implants was not strictly followed [ 3 ]. Bacteria are capable of forming a biofilm structure, thus protecting themselves against the environment and the human immune system [ 4 , 5 ]. At the implant site, an infection develops, which spreads to the whole body and may cause life-threatening complications [ 6 , 7 ].…”

Atmospheric Pressure Plasma Deposition of TiO2: A Review

“…Photons with sufficient energy can create an electron–hole pair, and, as a result, the excited electron in the conduction band reduces oxygen to superoxide, while the hole in the valence band oxidizes water molecules to hydroxyl ions [ 30 ]. Moreover, titania has high durability as well as chemical activity and stability under ultraviolet (UV) light [ 31 , 32 ], which, in addition to its water splitting ability, makes it useful for antimicrobial treatment, water purification, self-cleaning purposes [ 33 , 34 , 35 , 36 ], and material passivation [ 37 ]. The species formed through redox reactions at the surface are sufficiently powerful to decompose organic molecules or microbes, leading to the self-cleaning ability of TiO 2 .…”