The high expression of classically activated macrophages (M1) subtypes and the elevated levels of reactive oxygen species (ROS) are specifically observed in osteoarthritis (OA) patients. In this study, we synthesized a Pd@CeO2 nanozyme with a core-shell hetero-nanostructure that enhances enzyme activity through shell-core electron transfer. The goal of this work was to look into the potential of Pd@CeO2 nanozyme in scavenging ROS and regulating macrophages for the treatment of OA. The results demonstrated that the Pd@CeO2 nanozyme displayed multiple enzyme-like antioxidative activities, efficiently eliminating excessive intracellular ROS. This resulted in a significant decrease in the release of pro-inflammatory cytokines, consequently leading to a decline in the presence of M1-type macrophages. Furthermore, the Pd@CeO2 nanozyme showed excellent potential in promoting the shift of macrophages toward the M2 phenotype. Additionally, the factors secreted from the cell supernatant of Pd@CeO2-treated macrophages treated with Pd@CeO2 demonstrated anti-inflammatory properties in the chondrocytes located within inflamed synovial joints. These findings offer valuable insights into the advancement of effective enzyme-mimetic therapies for the treatment of OA.
Zhan et al. (2026) studied this question.