Inflammatory proteins in infected bone tissue - An explorative porcine study

Area of Science:

• Biomedical Engineering
• Orthopedic Surgery
• Molecular Biology

Background:

• Implant-associated osteomyelitis is a significant clinical challenge.
• Understanding the local inflammatory environment is crucial for effective treatment.

Purpose of the Study:

• To investigate the in situ inflammatory protein profile in infected bone tissue extracellular fluid.
• To assess the utility of microdialysis for sampling inflammatory markers in osteomyelitis.

Main Methods:

• A porcine model of Staphylococcus aureus osteomyelitis was established.
• Microdialysis catheters were inserted into infected and healthy bone and subcutaneous tissue.
• An antibody-based proximity extension assay (Olink Inflammatory panel) was used to measure protein levels.

Main Results:

• Proteins associated with angiogenesis and bone remodeling (OPG, TGFα, VEGFA, uPA, MCP-1) were upregulated in infected bone.
• Systemic and local inflammatory markers showed parallel detectability, validating microdialysis.
• The study identified a distinct angiogenic and osteogenic inflammatory protein signature in infected bone.

Conclusions:

• Microdialysis is a viable method for in vivo protein analysis of the extracellular environment in infected bone.
• The identified protein composition supports existing histopathological findings in osteomyelitis.
• This approach offers insights into the local inflammatory milieu of bone infections.