Photodriven PtPdCo-TiO2 heterostructure modified with hyaluronic acid and folic acid enhances antioxidative stress through efficient hydrogen/oxygen delivery and thermal effects in rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic synovitis and progressive joint damage, primarily caused by oxidative injury from reactive oxygen species (ROS) and hypoxia in immune cells. Hydrogen (H2) has demonstrated potential in scavenging excess ROS and correcting redox imbalances, while oxygen supplementation can alleviate hypoxia, promoting inflammatory remission. This study introduces a novel FA-HA-PtPdCo-TiO2 (F-HPPCT) nano-system for targeted RA therapy. Comprising TiO2 quantum dots on PtPdCo polyhedra, decorated with folate-hyaluronic acid (FA-HA), F-HPPCT selectively targets inflammatory cells. Its metal-semiconductor heterostructure forms Schottky junctions that enhance electron transfer, enabling efficient hydrogen evolution and a photothermal effect under near-infrared light. Additionally, F-HPPCT mimics catalase activity, decomposing overexpressed H2O2 to relieve hypoxia and oxidative stress. The system synergistically scavenges ROS and replenishes oxygen, effectively reducing inflammation and oxidative damage. Both in vitro and in vivo experiments in arthritis models confirmed its efficacy, highlighting F-HPPCT's potential as a groundbreaking nanocatalyst for gas therapy in RA treatment.