Session I - Basic Science

Antimicrobial Activity of NanoSilver Bone Cement Against Multiresistant Bacteria Volker Alt, MD¹; Thorsten Bechert, PhD²; Peter Steinruecke, PhD²; Elvira Dingeldein, PhD³; Peter Seidel, PhD³; Reinhard Schnettler, MD¹;

¹Department of Trauma Surgery, University Hospital Giessen, Germany;

²Bio-Gate, Nuremberg, Germany;

³Coripharm, Dieburg, Germany

Purpose: Infection with multiresistant bacteria is a severe complication in bone and joint surgery. Other authors have already reported on bone cement with silver salts added to inhibit bacterial proliferation. However, the cell toxicity of the released silver salt ions made this kind of silver bone cement unsuitable for everyday clinical use. This study was undertaken to evaluate in vitro antimicrobial activity and in vitro cytotoxicity of polymethylmethacrylate (PMMA) bone cement loaded with metallic silver particles with a size of 50 to 100 nanometers called NanoSilver.

Methods: In vitro antimicrobial activity of nanoparticulate silver bone cement against Staphylococcus epidermidis, Staphylococcus aureus, multiresistant Staphylococcus epidermidis (MRSE), and multiresistant Staphylococcus aureus (MRSA) was studied with use of microplate proliferation testing. Use of bone cement with or without antibiotic loading served as controls. Ongrowth of osteoblasts on the different bone cements and cell lysis of mice fibroblasts in elution testing of the bone cements was used to study in vitro cell toxicity.

Results: NanoSilver bone cement showed antimicrobial activity against S. epidermidis, S. aureus, MRSE, and MRSA that was dose-dependent. Gentamicin-containing bone cement was not effective against MRSA or MRSE. Bone cement without silver or antibiotics did not inhibit proliferation of any strains. There also was no significant difference in elution testing of the silver cement compared with plain bone cement. There was also no difference in cell ongrowth of osteoblasts on the cement between NanoSilver and plain bone cement. Therefore, bone cement added with nanoparticulate silver was not cytotoxic.

Conclusions: NanoSilver bone cement showed in vitro antimicrobial activity against S. epidermidis, S. aureus, MRSE, and MRSA in the absence of in vitro cytotoxicity. If the results of the current study can be confirmed in vivo, NanoSilver may be of high interest for use in total joint arthroplasty, particularly due to its effect against multiresistant bacteria.