Meniscus-Inspired Self-Lubricating and Friction-Responsive Hydrogels for Protecting Articular Cartilage and Improving Exercise.

Meniscus injuries are associated with the degeneration of cartilage and development of osteoarthritis (OA). It is challenging to protect articular cartilage and improve exercise when a meniscus injury occurs. Herein, inspired by the components and functions of the meniscus, we developed a self-lubricating and friction-responsive hydrogel that contains nanoliposomes loaded with diclofenac sodium (DS) and Kartogenin (KGN) for anti-inflammation and cartilage regeneration. When the hydrogel was injected into the meniscus injury site, the drug-loaded nanoliposomes were released from the hydrogel in a friction-responsive manner and reassembled to form hydration layers that lubricate joints during movement. Meanwhile, DS and KNG were constantly released from the nanoliposomes to mitigate inflammation and promote cartilage regeneration. Additionally, this hydrogel exhibited favorable injectability, mechanical properties, fatigue resistance, and prolonged degradation. In vivo experiments demonstrated that injection of the hydrogel effectively improved exercise performance and protected the articular cartilage of rats, suggesting it as a potential therapeutic approach for meniscal injuries.