Electrospray Deposition of Antimicrobial Nano-Powder/Bioactive Glass Composites on Ti6Al4V Implants

Introduction. Bone infections after orthopaedic surgery especially implant releated osteomyelitis still one of the most important problem of Orthopaedics and Traumatology. Several techniques and methods have been developed to... [ view full abstract ]

Introduction. Bone infections after orthopaedic surgery especially implant releated osteomyelitis still one of the most important problem of Orthopaedics and Traumatology. Several techniques and methods have been developed to prevent infection. In this study, Ti6Al4V implants were electrospray coated by metal ion doped calcium phosphate based antimicrobial nano-powder (ABT) and bioactive glass (BG) to prevent local infections.
Methods. Antimicrobial powders were synthesized by using wet chemical method. Calcium oxide and orthophosphoric acid were used as source of Ca2+ ion and PO43- ion, respectively. Ag+ ion was used as antimicrobial agent. Bioactive glass was prepared by mixing and firing the required reagents using a standart procedure. Halo Test Method was used to determine antimicrobial activity of powders. The BG powder was suspended in non aqueous medium. This suspension was deposited on substrates by dip coating. Then a vertical configuration of the ESD set-up was performed to deposit antimicrobial powder on implants. After deposition, electrospray deposited samples were sintered for 20-30 seconds by RF sintering unit under high vacuum. Surface characteristic of coated samples were investigated by Scanning Electron Microscopy (SEM, Zeiss Supra 50VP) and metal ion content of coatings were determined by Energy Dispersive X-Ray Spectroscopy (EDX). The adhesion of the coatings to the substrate was evaluated through the scratch test technique.
Results and Discussion. In vitro antimicrobial tests indicate that the synthesized powder provides efficient antimicrobial effect. SEM images showed that the ABT/BG coatings form a continuous coating on Ti6Al4V surface. The result of scratch tests provided that the critical load of ABT/BG coating was indicated a high adhesive strength exists between coating and substrate. The results showed that bioactive glass with antibacterial ceramic powder has better adhesion and mechanical properties.
Conclusions. In this study, an antimicrobial nano-powder/bioactive glass coating was successfully prepared on titanium alloy surface. As a surface coating material to host the silver ions, antimicrobial nano-powder and bioactive glass have several advantages that may benefit its usefulness as implants such as good biocompatibility, good mechanical property, easy manufacturability. In conclusion, the ABT/BG coatings may have potential application in Orthopaedics and Traumatology Surgery.