Reshaping the Inflammatory Environment in Rheumatoid Arthritis Joints by Targeting Delivery of Berberine with Platelet‐Derived Extracellular Vesicles

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by inflammation and joint destruction. Herein, an inflamed joint‐targeting delivery platform is developed based on platelet‐derived extracellular vesicles (PEVs) that are naturally occurring nanoparticles released by platelets, loaded with berberine (BBR) for suppressing the progress of RA. It is found that PEVs could selectively target the inflamed arthritis site in RA mice. In addition, BBR‐loaded PEVs exert anti‐inflammatory effects by reshaping the inflammatory environment in affected joints. It is shown that intravenous injection of BBR‐loaded PEVs into RA mice can effectively reduce joint swelling and bone erosion and restore mobility compared with free drug therapy. This strategy can effectively enhance the efficacy of RA treatment with limited side effects.