Hydrogels for ameliorating osteoarthritis: Mechanical modulation, anti-inflammation, and regeneration

Osteoarthritis (OA) is a chronic and degenerative disease with limited clinical options for effective suppression. Recently, significant endeavors have been explored to reveal its pathogenesis and develop treatments against OA. Hydrogels, designed with a striking resemblance to the extracellular matrix, offer a biomimetic interaction with biological tissues, presenting a promising avenue for OA amelioration. As a result, biocompatible hydrogels have been erected incorporating on-demand bioactivities to optimize the intra-articular microenvironment, thereby alleviating OA symptoms and fostering the eventual regeneration of articular joints. This review highlights the collaborative objectives underlying the establishment of this tissue microenvironment, encompassing mechanical modulation, anti-inflammation, and tissue regeneration. Specifically, we consolidate recent advances in hydrogel-based biomaterials, serving as the tissue engineering scaffolds to replicate the lubrication properties of natural joints or the bioactive agent-loaded vehicles to combat localized inflammation. Additionally, hydrogels function as cell scaffolds to facilitate the maintenance of cellular homeostasis and contribute to the advancement of cartilage regeneration. Finally, this review outlines the prospective directions for hydrogel-mediated OA therapies.