Agluna® is an innovative surface treatment technology applied during the manufacture of titanium implantable medical devices to assist in improving clinical outcomes by means of reducing the incidence and severity of near-term post-operative infection(8)(9). Supported by a strong patent portfolio, the technology has been in clinical use since 2006 with an increasing range of custom and modular titanium limb salvage systems, as well as other clinical applications such as titanium cranioplasties.
The use of silver on medical devices has previously been approved by worldwide regulatory bodies on an expanding range of products, though it is the silver ion that is the “active” form. The Agluna® silver ion based treatment reduces the risk of post-operative infection by reducing the risk of biofilm formation on the implant surface, due to its well-known antimicrobial properties. There is an associated release of silver ions from the implant’s surface by dissolution into body fluids during the first few weeks and months following surgery, when patients are at highest risk of post-operative infection. Silver ions have been reported to eliminate pathogens associated with medical device related infection, at relatively low doses, with no severe toxicological effect on the local tissues or systemically within the patient. By comparison with antibiotics, silver ions have also displayed relatively limited susceptibility to antimicrobial resistance. The distinctive purple anodised titanium oxide film gives the Agluna®-treated implant an improved durability and wear resistant surface based upon laboratory studies.
A comprehensive suite of in vitro and in vivo testing has been undertaken, confirming the safety and efficacy of t
he Agluna® surface treatment, e.g. (10). There are a number of publications reporting upon the clinical use of Agluna®-treated implants for the prevention of near-term post-operative infection, including a comprehensive matched cohort, retrospective study of megaprostheses confirming a notable reduction in near-term infection rate in high infection risk cases(11).
The Agluna® treatment of implants is achieved by an electrochemical process that involves high voltage anodisation (formation of an oxide layer integral with the metal surface) of the titanium implant in dilute phosphoric acid, followed by ion exchange with silver from an aqueous solution. This treatment results in the formation of circular features of approximately 5 µm diameter in the surface 
of the implant, containing an amorphous titania species within which the bulk of the ionic silver has been stored. In addition to the beneficial integration of ionic silver into the surface, the anodisation of titanium gives the Agluna®-treated implant a distinctive shiny violet appearance and enhances the durability of the material in laboratory tests.
The concentration of silver ions added to the implant surfaces by the Agluna® process is carefully controlled and is well below concentrations that would cause any potential toxicological side effects.