Bimetallic Metal–Organic Framework for Mitigating Aseptic Osteolysis

Abstract

The disability rate of joint diseases can be reduced by the use of artificial joints, but joint loosening at a late state limits the lifespan and surgical efficacy of the joints. Wear particles can be recognized by macrophages and induce cells to produce reactive oxygen species (ROS) and inflammatory factors, causing persistent inflammation and decreased osteogenic activity, which ultimately leads to loosening of joint prostheses. Here, the platinum (Pt) nanozymes with excellent ROS scavenging and anti-inflammatory capabilities were encapsulated in zinc imidazolium zeolite framework-8 (ZIF-8), and then the osteogenic active element lanthanum (La) was introduced through ion exchange to finally construct a bimetallic metal-organic framework (Pt@ZIF-8@La). In vitro and in vivo experiments demonstrated that this multifunctional nanoplatform possessed the functions of efficient scavenging of ROS, immune regulation, and promotion of osteogenic differentiation. Meanwhile, the mechanism is explored that Pt@ZIF-8@La can also promote osteogenic mineralization by upregulating the ratio of the osteoprotegerin (OPG)/receptor activator of the NF-κB ligand (RANKL), which can achieve a synergistic therapeutic effect of immunomodulation and osteogenesis, thereby realizing the purpose of relieving aseptic osteolysis.