Nanocarriers such as enzyme-responsive nanoparticles (PRNPs) made up of RGD-modified PLGA nanoparticles (RNPs) covered with MMP-9-cleavable PEG chains enable celastrol to decrease the number of osteoclasts and inflammatory macrophages in rat models with RA, as well as promoting high cellular uptake in RA human synovial macrophages and osteoclasts resulted from patients undergoing joint replacement surgery. This evidence concerns the gene MMP9 and rheumatoid arthritis.