In Vivo Imaging of Particle-Induced Inflammation and Osteolysis in the Calvariae of NF B/Luciferase Transgenic Mice

Wear debris causes biological response which can result in periprosthetic osteolysis after total joint replacement surgery. Nuclear factor-kappa B (NFB), a representative transcription factor involved in inflammation, is believed to play an important role in this event by regulating the production of proinflammatory mediators and osteoclastogenesis. In this study, we sought to determine whether activation of NFB in response to stimulation by particles could be visualized by in vivo imaging. We loaded polyethylene (PE) particles onto the calvaria of NFB/luciferase transgenic mouse, and detected luminescence generated by activation of NFB. On day 7 after loading, the level of luminescence was maximal. Levels of luminescence were significantly correlated with the levels of luciferase activity, proinflammatory mediator mRNAs, and bone resorption parameters. This system, which enabled us to evaluate particle-induced inflammation and osteolysis without sacrificing mice, constitutes a useful tool for evaluating the efficacy of prophylaxis or treatments for particle-induced osteolysis.