Melanie Nonhoff (Münster / DE), Jan Pützler (Münster / DE), Manfred Fobker (Münster / DE), Silke Niemann (Münster / DE), Julian Hasselmann (Münster / DE; Steinfurt / DE), Georg Gosheger (Münster / DE), Martin Schulze (Münster / DE)
Question
Periprosthetic joint infections (PJI) are more likely to occur with increasing implant volume, which can lead to clinical challenges due to the need for multiple revision surgeries. Currently, only a few anti-infective implant coatings are in clinical use with the aim to reduce this risk [1]. Furthermore, biofilm growth on the implant surface is not adequately inhibited by systemic antibiotic treatments.
A biocompatible implant coating with an anti-infective concentration of homogeneously dissolved silver ions has been developed to prevent biofilm formation on the implant surface. Additionally, extracorporeal shock waves (ESW) can be used to non-invasively activate the targeted burst-release of silver ions into the vicinity of the implant at any time.
Methods
The study analyzed the two modes of operation. Biofilm inhibition assays were conducted using Staphylococcus epidermidis RP62A. The silver released by activation with ESW was analyzed using graphite furnace atomic absorption spectrometry (GF-AAS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), confocal laser scanning microscopy (CLSM) and growth curve analysis. Additionally, a combined biofilm and activation assay was also performed.
Results
The biofilm of S. epidermidis was inhibited by 1000-fold with a 6% silver coating. Activation resulted in the release of 57.8 ± 0.04738 mg/L of silver. SEM, EDX and CLSM analyses indicate complete local release of Ag by disrupting small areas of the coating. The analysis of the growth curve revealed a delay of 12 hours in growth. The combination of both modes resulted in complete eradication after 24 hours.
Conclusions
This implant coating has the potential to protect against PJI and enables non-invasive activation to release silver in a targeted and controlled manner. The coating could be a complementary treatment option to systemic antibiotics for PJI.
References
[1] Wildemann B, Jandt KD (2021) Infections @ Trauma/Orthopedic Implants: Recent Advances on Materials, Methods, and Microbes-A Mini-Review. Materials (Basel) 14. https://doi.org/10.3390/ma14195834