Hydrogel-based drug delivery systems for rheumatoid arthritis treatment

• Hydrogels with three-dimensional network structures enable precise drug delivery to the lesion and prolonged retention in the joint cavity, making them ideal carriers for rheumatoid arthritis therapy. • Stimulus-responsive hydrogels (e.g., pH, reactive oxygen species, matrix metalloproteinase responsive) significantly enhance targeted and controlled drug release, reducing systemic toxicity and enabling on-demand drug delivery in the inflammatory microenvironment. • Microneedle transdermal delivery systems combined with hydrogel matrices overcome skin barrier limitations, achieving efficient local delivery of macromolecular drugs and biologics, offering a non-invasive treatment approach. • Stem cell-hydrogel composite systems simultaneously exert anti-inflammatory and tissue repair effects, showing synergistic efficacy in improving immune imbalance and promoting cartilage regeneration.