Infection of endoprostheses is a serious complication in orthopedic surgery. As silver is known for its antibactierial effects, silver-coated endoprostheses have gained increased attention to decrease infection rates. However, cytotoxic effects of silver on bone cells have not been investigated in detail. We aimed to investigate whether silver nano-/microparticles and ionic silver exert cytotoxic effects on osteoblasts and osteoclasts in vitro and to correlate potential effects with the antibacterial effect on Staph. epidermidis. Murine osteoclasts (OC) and murine osteoblasts (OB) were treated with silver particles (avg. sizes: 50nm, 3μm, 30μm, 8μg/ml–500μg/ml) and Ag+NO3- (0.5μg/ml–500μg/ml). Silver treatment started on day 3 to prevent interference with cell adhesion. XTT assays were performed to assess cell viability. Tartrate resistant acidic phosphatase (TRAP) activity and alkaline phosphatase (ALP) activity served as measures for OC and OB differentiation, respectively. The release of silver ions from silver particles was quantified with atomic emission spectometry (AES). Titanium particles (avg. sizes: 50nm and 30μm) were used as controls to investigate whether potential silver effects were particle- or ion-mediated. The antimicrobial activity of silver ions and particles was tested with Staph. epidermidis agar inhibition assays.Introduction
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