Injectable hydrogel with persistent interfacial lubrication and anti-inflammatory for osteoarthritis therapy.

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by lubrication failure of cartilage interface and synovial inflammation. However, current injectable biomaterials rarely provide long-lasting lubrication while achieving sustained anti-inflammatory therapy. Herein, we developed a persistent interfacial lubrication hydrogel (CPD-OD/MSN@AP) through dynamic Schiff base crosslinking of a hydration enhanced chitosan derivative (CPD) and oxidized dextran (OD), with antler peptide-loaded mesoporous silica nanoparticles (MSN@AP) incorporated into the network. The resulting hydrogel exhibited rapid gelation, injectability, adaptive viscoelasticity, and favorable biodegradability under physiological conditions. Friction tests demonstrated that the hydrogel could reduce friction on both native and degenerated cartilage surfaces. More importantly, effective lubrication was largely maintained after hydrogel degradation because polymer fragments retained on the cartilage surface continued to preserve the interfacial hydration layer. Furthermore, intra-articular administration of CPD-OD/MSN@AP significantly alleviated cartilage degeneration, and reduced inflammatory factor expression in rat OA model. By integrating persistent lubrication with sustained biological regulation, this work provides a promising strategy for the development of injectable lubricating hydrogels for joint protection and OA treatment.