An ROS-responsive artesunate prodrug nanosystem co-delivers dexamethasone for rheumatoid arthritis treatment through the HIF-1α/NF-κB cascade regulation of ROS scavenging and macrophage repolarization

The signaling cascade between nuclear factor-kappa B (NF-κB) and hypoxia-inducible factor-1α (HIF-1α) can be activated by proinflammatory M1 macrophages in rheumatoid arthritis (RA), which produces reactive oxygen species (ROS) and enhances M1 macrophage polarization, thus aggravating the development of RA. Therefore, an ROS-responsive artesunate prodrug micellar nanosystem for co-delivery of dexamethasone (DEX/HA-TK-ART micelles, abbreviated as DEX/HTA) was developed for synergistic inhibition of the HIF-1α/NF-κB cascade to regulate ROS scavenging and macrophage repolarization in RA combination therapy. DEX/HTA micelles displayed prolonged circulation in blood and efficiently co-delivered ART&DEX in the inflamed joints of adjuvant-induced arthritis (AIA) rats; moreover, they were specifically recognized and internalized into M1 macrophages through CD44 receptor-mediated endocytosis. ROS-responsive co-released ART&DEX then exerted a synergistic action to efficiently perform ROS scavenging and repolarization of M1 to M2 macrophages by inhibition of the HIF-1α/NF-κB cascade. The intravenous administration of DEX/HTA micelles into AIA rat models significantly alleviated inflammatory cell infiltration and repaired cartilage injury in the joint. Collectively, our study highlights the therapeutic potential of DEX/HTA micelles for treating RA through synergistic inhibition of the HIF-1α/NF-κB signaling cascade to regulate ROS scavenging and macrophage repolarization. STATEMENT OF SIGNIFICANCE: An ROS-responsive artesunate (ART) prodrug micellar nanosystem for co-delivering dexamethasone (DEX), abbreviated as DEX/HA-TK-ART micelle, was developed for synergistic cascade regulation of the HIF-1α/NF-κB pathway on ROS scavenging and macrophage repolarization in combination therapy for rheumatoid arthritis. The well-designed nanosystem showed prolonged circulation in blood and superior ART&DEX accumulation in the inflamed joints of AIA rats; moreover, the micelles were specifically internalized into M1 macrophages and co-released ART&DEX, subsequently leading to inhibition of the HIF-1α/NF-κB pathway for ROS scavenging and macrophage repolarization, thus generating synergistic anti-inflammatory effects in RAW 264.7 cells and AIA rats. The HIF-1α/NF-κB cascade regulation on ROS scavenging and macrophage repolarization based on ART&DEX combination with smart nanotechnology could serve as a promising approach for rheumatoid arthritis therapy.