Prävention Implantat-assoziierter Infektionen mittels innovativer Beschichtung; Akronym: CUVER; Subproject Nr. 4: Präklinische Untersuchung einer antimikrobiellen Oberflächentechnologie auf Kupferbasis im Kleintier-Knochenheilungsmodell

Abstract

This investigation is part of the collaborative research project CUVER, supported by BMBF grant ‘Innovative medizintechnische Lösungen zur Prävention und Versorgung nosokomialer Infektionen’ (13GW0427D). Participating partner institutions of CUVER are DOT GmbH (as coordinator), STRYKER Trauma GmbH, Julius Wolff Institute, Charité, and UKSH. The objective of this subproject is to establish in a small-animal rat fracture model that implantation of copper-coated titanium intramedullary nail has no negative influence on the bone healing process in fracture repair. Longitudinal optical imaging of neutrophil elastase activity, as a marker of inflammation, and longitudinal micro-computed tomography to assess mineralization associated with callus and bone tissue formation, was performed. We show by optical imaging that neutrophil elastase activity decreases from day 5 to day 21 for both titanium and copper-coated titanium implants, indicating that inflammation is resolved or resolving. No differences in neutrophil elastase activity was observed between the two implants. Longitudinal micro-CT imaging revealed a steady increase in bone micromorphological parameters (BV/TV, BMC and BMD and TMC) for both implant materials. TMD shows a steady decrease down to around 92% with no significant difference between the groups. TMC vs. TMD are in good agreement with expectations for early mineralization in callus formation. The body weight of the rats for both groups of implants also increased steadily and was similar to the control group. In summary, following an acute inflammatory response, copper-coated implants do not induce chronic inflammation, do not negatively affect the bone healing process and show the same degree of biocompatibility as titanium implants