Reducing Staphylococcus aureus growth on Ti alloy nanostructured surfaces through the addition of Sn

Abstract

β-type Ti alloys containing Nb are exciting materials for numerous orthopedic and dental applications due to their exceptional mechanical properties. To improve their cytocompatibility properties (such as increasing bone growth and decreasing infection), the surfaces of such materials can be optimized by adding elements and/or nanotexturing through anodization. Because of the increasing prevalence of orthopedic implant infections, the objective of this in vitro study was to add Sn and create unique nanoscale surface features on β-type Ti alloys. Nanotubes and nanofeatures on Ti-35Nb and Ti-35Nb-4Sn alloys were created by anodization in a HF-based electrolyte and then heat treated in a furnace to promote amorphous structures and phases such as anatase, a mixture of anatase-rutile, and rutile. Samples were characterized by SEM, which indicated different morphologies dependent on the oxide content and method of modification. XPS experiments identified the oxide content which resulted in a phase transformation in the oxide layer formed onto Ti-35Nb and Ti-35Nb-4Sn alloys. Most importantly, regardless of the resulting nanostructures (nanotubes or nanofeatures) and crystalline phase, this study showed for the first time that adding Sn to β-type Ti alloys strongly decreased the adhesion of Staphylococcus aureus (S. aureus; a bacteria which commonly infects orthopedic implants leading to their failure). Thus, this study demonstrated that β-type Ti alloys with Nb and Sn have great promise to improve numerous orthopedic applications where infection may be a concern.

Developing a New Beta‐Type of Ti–Si/Sn Alloys for Targeted Orthopedic Therapeutics: Assessments of Biological Characteristics

“…[21][22][23] Furthermore, upon infusion of Sn, surfaces of β-type Ti alloys reportedly display unique nanoscale characteristics, which can significantly inhibit the adhesion and growth of certain bacteria. [24] These findings suggest that Sn and its Ti alloys might be appropriate alternatives for conventional Ti alloys. Beta-Ti alloys are promising materials for load-bearing orthopedic implants due to their excellent corrosion resistance and biocompatibility, low elastic modulus, and moderate strength.…”

Modification of Anodic Titanium Oxide Bandgap Energy by Incorporation of Tungsten, Molybdenum, and Manganese In Situ during Anodization

“…Likewise, doping of anodic TiO 2 realized during anodization by substrate elements has found applications not only in photocatalysis, but also in biomedicine. The composition of β-type biomedical titanium alloy substrates was modified by other elements (such as Ti-30Ta [ 49 ], Ti–7.5Mo [ 50 ], Ti-15Mo [ 51 ], and Ti-35Nb and Ti-35Nb-4Sn [ 52 ]) with subsequent anodization to improve the biological response of those materials. In all the abovementioned studies [ 49 , 50 , 51 , 52 ], nanotubular structures grew on top of the alloy, and its biomedical performance was improved in comparison to un-anodized samples.…”

Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

“…1 Titanium and titanium alloys are used as implant biomaterials due to their biocompatibility, mechanical strength, and noncorrosive properties. 2–5 However, nosocomial microbial attachment to the implant surface can result in infection and inflammation with implant loosening that requires surgical revision. In the first hours following surgery the implant surface is most vulnerable to bacterial colonization and the bacterial pathogens are also most susceptible to antimicrobial treatment.…”

“…However, the rise of antibiotic resistance is lately becoming a major concern in dealing with bacteria, which also led to an increase in efforts to find alternative strategies. 2–5 Silver, polyethylene glycol (PEG), or quaternary ammonia-based compounds (QACs) have been among the well-studied examples to bring the antimicrobial property by attaching them to the biomaterials using covalent chemical bonds. 12–17 Another strategy is to improve the antibacterial properties of metals by doping them with elements such as bismuth and zinc.…”