Recent trends in stimuli-responsive hydrogels for the management of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory condition triggered by abnormal autoimmune responses. Key characteristics of RA include the deterioration of joints and bones, immune cell activation within the synovium, and the erosion of articular cartilage. The global prevalence of RA stands at 0.24%, with a higher incidence rate among women (3.6%) compared to men (1.7%). Currently available treatments options include disease-modifying anti-rheumatic medications (DMARDs), biologic DMARDs, and synthetic compounds, are limited by their short half-life, the need for frequent administration, and the significant adverse effects resulting from non-specific uptake. Moreover, the conventional drug delivery approach is unspecific delivery at desired target area which results in systemic toxicity. Among the various drug delivery systems available, stimuliresponsive hydrogels stand out as a particularly promising platform for addressing the limitations of traditional medications. These stimuli-responsive hydrogels can be categorized into cattegories based on their responsiveness to various signals or stimuli, such as changes in pH, temperature, reactive oxygen species (ROS), and near-infrared radiation (NIR). In this comprehensive review, we have extensively explored recent advancements in research regarding stimuli-responsive hydrogels and their potential applications as carriers for drug delivery in the context of RA treatment. We have also delved into the progress made in formulating various types of stimuli-responsive hydrogels. Employing stimuli-responsive hydrogels to treat inflammatory arthritis based on pathological changes including cartilage degradation, synovitis, and subchondral bone loss has resulted in progress, but there are still barriers to overcome. After an extensive review of a variety of in-vitro and in-vivo studies, we had reached to conclude that stimuli-responsive hydrogels hold significant promise as efficient drug carriers for the treatment and management of RA.