New Dawn in the Treatment of Rheumatoid Arthritis: Advanced Insight into Polymer Hydrogel Research.

As a chronic systemic autoimmune disease, rheumatoid arthritis (RA) not only damages joints and other organs or systems throughout the body but also torments patients' physical and mental health for a long time, seriously affecting their quality of life. According to incomplete statistics at present, the global prevalence of RA is approximately 0.5-1%, and the number of patients is increasing year by year. Currently, drug therapies are usually adopted for the treatment of RA, such as non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs (DMARDs), glucocorticoids/steroids, and so on. However, traditional drug therapy has problems such as long half-lives, long treatment cycles requiring frequent drug administration, lack of specificity, and other possible adverse reactions (such as gastrointestinal side effects, skin stratum corneum barrier damage, and systemic toxicity), which greatly restrict the treatment of RA. In order to improve the limitations of traditional drug, physical, and surgical treatments for RA, a large number of related studies on the treatment of RA have been carried out. Among them, hydrogels have been widely used in the research on the treatment of RA due to their excellent biocompatibility, mechanical properties, and general adaptability. For example, hydrogels can be injected into the synovial cavity of joints as synovial fluid to reduce wear between joints, lubricate joints, and avoid synovial surface degradation. This article reviews the applications of hydrogels in the treatment of RA under different functions and the situation of hydrogels as carriers in the treatment of RA through different drug delivery routes and confirms the outstanding potential of hydrogels as drug carriers in the treatment of RA, which has great research significance.