MMP‐9 is an important mediator that leads to RA synovial fibroblast survival, proliferation, migration and invasion.36 Thus, the inhibited production of MMP‐9 in the in vivo study suggests that HAP‐lipo/NBD is an effective agent for disrupting the SF‐mediated bone‐harming behaviour.37 Furthermore, the pathological analysis showed that HAP‐lipo/NBDs effectively inhibit cell hyperplasia in the synovial lining. This evidence concerns the gene MMP9 and rheumatoid arthritis.