Effectiveness of titanium nitride silver coatings against Staphylococcus spp. in the presence of BSA and whole blood conditioning agents

Fabien J Saubade,Sarah Hughes,David J Wickens,Joels Wilson-Nieuwenhuis,Nina Dempsey-Hibbert,Grace S Crowther,Glen West,Peter Kelly,Craig E Banks,Kathryn A Whitehead

doi:10.1016/j.ibiod.2018.06.016

Fabien J Saubade, Sarah Hughes + Show 8 more

Open Access

https://doi.org/10.1016/j.ibiod.2018.06.016

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Abstract

Implanted medical devices are at risk of developing an infection at the surgical site. Once a medical implant is inserted, it initially becomes coated by a conditioning film, followed by bacterial retention. In the present study, medical grade stainless steel substrata were coated with titanium nitride (TiN) or titanium nitride/silver (TiN/14.94 at.%Ag or TiN/19.04 at.%Ag). Surface analysis determined that with increased silver concentration, silver nanoparticles were heterogeneously distributed throughout the coatings. The effect of bovine serum albumin or whole blood conditioning agents on the antimicrobial activity and microbial retention were determined using Staphylococcus aureus or Staphylococcus epidermidis. The presence of the conditioning agents reduced the antimicrobial effect of the surfaces against S. aureus. When the cells and conditioning agents were applied together, a reduction in bacterial retention and conditioning film was observed. These results suggest that the impact of conditioning agents should be considered since conditioning films may reduce bacterial retention but may also decrease the antimicrobial properties of the surface coatings.

Highlights

IntroductionOrthopaedic devices such as fine-wire fixators and external fixators are commonly use for the treatment of long bone fractures and pelvic fractures for both adults and children (Ktistakis et al, 2015)
External fixations are essential components of modern orthopaedic surgery
When the cells and conditioning agents were applied together, a reduction in bacterial retention and conditioning film was observed. These results suggest that the impact of conditioning agents should be considered since conditioning films may reduce bacterial retention but may decrease the antimicrobial properties of the surface coatings

Summary

Introduction

Orthopaedic devices such as fine-wire fixators and external fixators are commonly use for the treatment of long bone fractures and pelvic fractures for both adults and children (Ktistakis et al, 2015). External fixations are associated with a high incidence of pin tract infection rates (Ktistakis et al, 2015; Schalamon et al, 2007). Some pathogenic strains of common skin microbiota species, such as Staphylococcus aureus and Staphylococcus epidermidis, can grow in these biofilms and be involved in pin tract infections. Schalamon et al (2007) found that among 37 external fixations placed on 30 children, 19 (52%) led to at least one infection. S. aureus and S. epidermidis were found in 33% and 22% of the paediatric pin tract infections respectively

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