Antimicrobial metals and metal-based particles for biomedical applications

Student thesis: Doctoral ThesisDoctor of Philosophy


Titanium and titanium alloys have emerged as excellent candidates for use as orthopaedic implants, such as hip and knee arthroplasties (joint replacements). Two of the most common causes of implant failure include infection and aseptic loosening, which is caused by a lack of biological compatibility. In this work, laser surface modification was employed throughout this thesis as a fast, robust and scalable approach to combatting these issues. Microbiological studies illustrated laser surface treated titanium alloys possess both bactericidal and anti-adherent properties. Laser surface treatment of titanium alloys was found to not compromise cell viability and in some cases, significantly increase cell viability upon surfaces that were laser treated, relative to untreated titanium. Throughout the lifecycle of an orthopaedic implant, the repeated articulation gives rise to ‘wear particles’ as a result of the friction generated between the implant and the surrounding tissue. Wear particles were generated using pin-on-disc tribometry to determine whether there is a difference between the wear debris generated from untreated and laser-treated samples. The wear debris generated from laser-treated samples were found to possess antibacterial properties against both Staphylococcus aureus and Escherichia coli. Further research focused upon investigating laser ablation in liquid, in which a novel method of nanoparticle synthesis was performed that can be harnessed to synthesise nanoparticles with unique physicochemical properties for biomedical applications. Silicone polymers have a wide range of biomedical applications yet are still prone to infection. A range of novel silicone nanocomposites were synthesised containing broad spectrum antimicrobial nanoparticles (Cu, Zn, Ti, TiO2) in an effort to mitigate infection. Silicone nanocomposites were assessed for their antimicrobial properties and cytocompatibility to determine whether they have any promise as medical devices. Several candidates, particularly Cu-containing silicone nanocomposites, retained biocompatibility whilst boasting antimicrobial properties, offering a new avenue for addressing medical device-associated infections.

Thesis is embargoed until 31 July 2027.

Date of AwardJul 2023
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsNorthern Ireland Department for the Economy
SupervisorLouise Carson (Supervisor), Chi Wai Chan (Supervisor) & Matthew Wylie (Supervisor)


  • Biomaterial
  • titanium
  • orthopaedic
  • antibacterial
  • surface modification
  • silicone
  • laser

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