Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Mimicking the Dragonfly Wing-Like Structure as an Antimicrobial Surface for Orthopaedic Devices (#248)

Alex Barker 1 , Helen Tsangari 1 , Richard Bright 2 3 , Claire F Jones 4 , Ryan D Quarrington 4 , Dan Barker 5 , Toby Brown 5 , Krasi Vasilev 2 3 , Paul H Anderson 1
  1. Clinical & Health Sciences, University of South Australia, Adelaide, SA, Australia
  2. Future Industries Institute, University of South Australia, Adelaide, SA, Australia
  3. STEM, University of South Australia, Adelaide, SA, Australia
  4. Centre for Orthopaedic & Trauma Research, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
  5. Corin Australia, Baulkham Hills, NSW, Australia

Periprosthetic Joint Infection (PJI) is defined as an infection involving the joint prosthesis and adjacent tissue. More than 1% of primary hip and 1 to 3% of primary knee arthroplasties fail due to PJI leading to ongoing morbidities and mortality. A recent discovery that the dragonfly wing surface structure naturally kills bacteria has led to recreating this passive nano-textured surface on titanium alloy (Ti6Al4V). The aim of this study was to assess the anti-microbial and osseointegration properties of the nano-textured Ti6Al4V implants using in vitro and pre-clinical in vivo models. Nano-textured Ti6Al4V, when incubated with Staphylococcus aureus (S. aureus) or Pseudomonas aeruginosa (P. aeruginosa), exhibited 60% and 98% reduction in live cells respectively, when compared to levels on control Ti6Al4V surface. To validate these findings, 12-week-old male rats underwent bilateral hindlimb surgery to insert rod-shaped implants (nano-textured or control Ti6Al4V) pre-coated with S. aureus (102-104 colony forming units (CFUs)) into each femur. Secondly, 8-week-old mice, received disc or pill-shaped implants pre-coated with 104 CFUs S. aureus and inserted in the subcutaneous space, to assess activity in a soft tissue environment. Implants from these two in vivo models are under evaluation for bacterial load, confocal and SEM imaging. Lastly, to assess osseointegration, the nano-textured Ti6Al4V implants were surgically inserted into tibial cortical and femoral cancellous bone in sheep, with implant integration assessed after 12-weeks using histomorphometric and biomechanical push-out analyses. When compared to porous ceramic hydroxyapatite (PCHA)-coated commercially available control implants, nano-textured Ti6Al4V implants had a significantly higher cortical bone contact surface, interface shear strength, peak load, failure load, and proof resilience, when compared to the PCHA coated implants. To date, these studies suggest that the nano-textured Ti6Al4V surface has clinical potential for medical devices that have orthopaedic applications and anti-microbial properties.