Cold Plasma Activity Against Biofilm Formation of Prosthetic Joint Infection Pathogens

Periprosthetic joint infections occur in 1-2% of all patients undergoing prosthetic joint surgeries. Although strong efforts have been made to reduce infection rates, conventional therapies like one- or two-stage revisions have failed to lower the infection rates. Cold atmospheric plasma (CAP) has shown promising results in reducing bacterial loads on surfaces. In this study, we aimed to investigate the ability of CAP to reduce the bacterial load on metal surfaces with varying distances and different plasma compositions below a temperature suitable for in vivo applications. Methods: Biofilm was formed with <i>Staphylococcus aureus</i> ATCC 29213 and <i>Staphylococcus epidermidis</i> ATCC 12228 cultures on TMZF discs. Plasma treatments using air plasma and argon plasma were conducted on discs containing the established biofilm while the temperature was measured. During the experiments, the duration and the distance of plasma application varied. Afterwards, colony-forming units were counted. Results: The results of this study showed that air and argon plasma could be considered for applications during surgeries at a 1 cm distance. While air plasma showed the highest efficiency in CFU reduction, the temperature generation due to the presence of oxygen poses a limitation concerning the duration of application. The use of argon as a plasma generator does not show the temperature limitation in correlation to exposure time. The use of air plasma with a distance of 1 cm to the application site and an exposure time of 5 s showed the most effective bacterial reduction while not exceeding tissue-damaging temperatures.