Suppression of NF-κB-induced chronic inflammation mitigates inflammatory osteolysis in the murine continuous polyethylene particle infusion model.

Wear particle-associated bone loss (periprosthetic osteolysis) constrains the longevity of total joint arthroplasty (TJA). Wear particles induce a prolonged upregulation of nuclear factor kappa B (NF-κB) signaling in macrophages and osteoclasts. Synthetic double-stranded oligodeoxynucleotides (ODNs) can prevent the binding of NF-κB to the promoter regions of targeted genes and inhibit genetic activation. We tested the hypothesis that polyethylene-particle induced chronic inflammatory bone loss could be suppressed by local delivery of NF-κB decoy ODNs in murine in vivo model. Polyethylene particles were continuously infused into the medullary cavity of the distal femur for 6 weeks to induce chronic inflammation, and micro-computational tomography and immunohistochemical analysis were performed. Particle-induced chronic inflammation resulted in lower BMD values, an increase in osteoclastogenesis and nuclear translocation of p65, a prolonged M1 pro-inflammatory macrophage phenotype, and a decrease of M2 anti-inflammatory macrophage phenotype. Delayed timing of local infusion of NF-κB decoy ODN for the last 3 weeks reversed polyethylene-particle associated chronic inflammatory bone loss and facilitated bone healing. This study demonstrated that polyethylene-particle associated chronic inflammatory osteolysis can be effectively modulated via interference with the NF-κB pathway; this minimally invasive intervention could potentially be an efficacious therapeutic strategy for periprosthetic osteolysis after TJA.