In this study, a triglycerol monostearate hydrogel (TG-18) loaded with the corticosteroid triamcinolone acetonide (TA) exhibited drug release in response to the increased activities of arthritis-related enzymes in vitro (MMP-2, MMP-3, MMP-9) or synovial fluid from patients with RA (Joshi et al., 2018). This evidence concerns the gene MMP9 and rheumatoid arthritis.