Lubricating and Dual-Responsive Injectable Hydrogels Formulated From ZIF-8 Facilitate Osteoarthritis Treatment by Remodeling the Microenvironment.

Osteoarthritis (OA) is a progressively developing condition primarily characterized by the deterioration of articular cartilage and the proliferation of bone, along with ongoing inflammation. Although the precise pathogenesis remains somewhat elusive, restoring the homeostatic balance of the intra-articular microenvironment is crucial for the management of OA. Intra-articular injection of medication is one of the most direct and effective treatment methods; however, most injectable drugs used for osteoarthritis treatment, due to their rapid breakdown, quick release, poor biological activity, and frequent injections, leading to increased risk of infection and suboptimal therapeutic outcomes. In this study, a lubricating and dual-responsive injectable hydrogel based on zeolitic imidazolate frameworks-8 (ZIF-8) impregnated with Quercetin (Que) is designed, which can facilitate OA treatment by remodeling the microenvironment. The prepared injectable nanocomposite hydrogel (MH/CCM@ZIF-8@Que) exhibits pH and reactive oxygen species (ROS) responsiveness, alongside a controllable release of bioactive substances to modulate the microenvironment of bone tissue, thereby mitigating synovitis and the degeneration of cartilage matrix, while simultaneously facilitating cartilage repair. This developed thermosensitive injectable hydrogel, which effectively balances lubrication with the controlled release of bioactive substances, represents a highly promising therapeutic approach for osteoarthritis.