C. Stotter (Krems, AT)
Danube-University Krems Center for Regenerative Medicine and OrthopedicsPresenter Of 1 Presentation
10.4.9 - The concentration-dependent effect of CoCr ions and particles on osteoarthritic chondrocytes
Abstract
Purpose
Cobalt (Co) and chromium (Cr) ions and particles are released into the joint after implantation of metal implants due to biotribocorrosion. Co and Cr can induce apoptosis and alter gene expression levels in various cell types. The objective of this study was to determine the effects of Co and Cr ions on human articular chondrocytes and to evaluate inflammatory responses.
Methods and Materials
Human articular chondrocytes were subjected to different concentrations of Co and Cr ions and particles. Cell viability and early/late apoptosis assessment were performed in-vitro(2D cell cultures) using XTT assay and flow cytometry, respectively. Changes in chondrocytes’ morphology were assessed using fluorescent cell imaging. In addition, the effects on the biosynthetic activity of chondrocytes were evaluated by quantitative polymerase chain reaction (qPCR). Inflammatory response to different conditions was determined by the release of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, IL-8).
Results
Cobalt and chromium ions and particles significantly reduce metabolic activity and induce early and late apoptosis (Annexin Vand 7-AAD) with increasing concentrations already after 24 hours in culture. After 72 hours the majority of chondrocytes (>90%) were apoptotic. SOX 9 expression was enhanced with increasing concentrations, whereas collagen type 2 showed a linear decrease after 24 hours. IL-8 release was enhanced with increasing Cobalt and chromium ions and particles levels, whereas IL-1β, IL-6, and TNF-α showed no significant differences between the applied conditions.
Conclusion
Co and Cr ions and particles show a dose-dependent and time-dependent effect on articular chondrocytes. With increasing concentrations, Co and Cr ions and particles induce apoptosis in articular chondrocytes, decrease metabolic activity and chondrocyte-specific gene expression, and induce an inflammatory response. Hence, these adverse effects on articular chondrocytes need consideration in cases of partial surface replacement and unicompartimental arthroplasty.