Microfluidic-engineering Prussian blue hydrogel microspheres for enhanced osteoarthritis antioxidant therapy.

Osteoarthritis (OA), a degenerative joint disorder and leading cause of global disabilty, imposes substantial societal and familial burdens. Current antioxidant therapies for OA are hindered by poor targeting and transient efficacy, failing to address the excessive reactive oxygen species (ROS)-driven pathogenesis. Herein, we innovatively integrate Prussian blue (PB) nanozymes with alginate-hyaluronic acid (HA) hydrogel microspheres through microfluidic engineering, creating the injectable AlgHA@PB platform that synergizes dual therapeutic mechanisms: ROS scavenging and oxygen generation via PB nanozymes, and sustained intra-articular retention and mechanical compatibility enabled by the hydrogel microsphere architecture. In vitro studies demonstrated that AlgHA@PB scavenged all of intracellular ROS while continuously releasing oxygen within. In a rat OA model, AlgHA@PB exhibited prolonged joint retention and reduced cartilage degeneration. Critically, the microspheres demonstrated a stable friction coefficient, enabling smooth intra-articular motion without mechanical irritation. This study establishes AlgHA@PB as a multifunctional OA therapeutic platform that integrates antioxidative defense, anti-inflammatory action, and biomechanical compatibility. The microfluidic-engineered design ensures scalable production, aligning with clinical translation requirements.