Both Enhanced Biocompatibility and Antibacterial Activity in Ag-Decorated TiO2 Nanotubes

Abstract

In this study, Ag is electron-beam evaporated to modify the topography of anodic TiO2 nanotubes of different diameters to obtain an implant with enhanced antibacterial activity and biocompatibility. We found that highly hydrophilic as-grown TiO2 nanotubes became poorly hydrophilic with Ag incorporation; however they could effectively recover their wettability to some extent under ultraviolet light irradiation. The results obtained from antibacterial tests suggested that the Ag-decorated TiO2 nanotubes could greatly inhibit the growth of Staphylococcus aureus. In vitro biocompatibility evaluation indicated that fibroblast cells exhibited an obvious diameter-dependent behavior on both as-grown and Ag-decorated TiO2 nanotubes. Most importantly, of all samples, the smallest diameter (25-nm-diameter) Ag-decorated nanotubes exhibited the most obvious biological activity in promoting adhesion and proliferation of human fibroblasts, and this activity could be attributed to the highly irregular topography on a nanometric scale of the Ag-decorated nanotube surface. These experimental results demonstrate that by properly controlling the structural parameters of Ag-decorated TiO2 nanotubes, an implant surface can be produced that enhances biocompatibility and simultaneously boosts antibacterial activity.

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].…”

“…As well, comparing Ag + release data and corresponding in vitro or in vivo response in the literature should be done cautiously, as quantification methods tend to vary among studies. The cytotoxicity and tissue cell response of novel Ag-TiO 2 nanotube coatings have been evaluated in recent studies, and demonstrated that a controlled release of Ag + can have sufficient antibacterial effect while maintaining, or in some instances even improving the biocompatibility [36,38,56]. The biological evaluation of the gradient coating presented in this work was limited to the effect against S. aureus bacteria, precluding the authors from drawing any conclusions regarding the mammalian cell response to the amount of Ag + released.…”

Corrosion resistance of superhydrophilic and superhydrophobic TiO2/epoxy coatings on AISI 316L stainless steel

“…3,4 However, to avoid their susceptibility to abrasion 5 and poor resistance to crack propagation, due to a highly cross-linked structure, 6 the basic idea is to enhance the mechanical properties and to promote the surface compatibility of the coating by incorporating different nanofillers. [7][8][9][10][11][12][13][14][15][16] It is mainly the favourable effects of the particle size, the volume fraction and the size distribution on the mechanical properties of composite coatings that have been studied. [17][18][19][20][21][22] Z.…”

Comparative study of superhydrophilic and superhydrophobic TiO2/epoxy coatings on AISI 316L stainless steel: surface properties and biocompatibility

“…1 The interaction of nanoscale surface topographies with cells was proven to play a crucial role in the biocompatibility of implants. 2 Various nanoscale surface modifications have been proposed in order to enhance the biocompatibility and antibacterial activity of medical implants. 3 Epoxy resins are widely used as long-term protective coatings for stainless steels in various applications.…”