Bioactive multifunctional hydrogel to ameliorate adverse joint microenvironment and enhance cartilage regeneration

Schematic illustration of the bioactive multifunctional hydrogel to ameliorate the adverse joint microenvironment and enhance cartilage regeneration. The schematic was produced with BioRender ( https://biorender.com/ ). • Osteoarthritis (OA) is a worldwide joint disease accompanied by progressive cartilage degradation and pathological microenvironment alterations. • We developed an RGD-modified hyaluronic acid methacryloyl (HAMA) hydrogel co-loaded with cartilaginous inducer Kartogenin (KGN) and anti-aging protein Klotho (HAMA-RGD@KGN/Klotho, HRKK) for comprehensive OA management. • Our bioactive multifunctional hydrogel showed dual therapeutic capabilities in both ameliorating OA-associated pathological conditions and enhancing cartilage regeneration. • This biomaterial-based strategy provides a promising clinical potential for preventing OA progression and achieving durable cartilage regeneration. Osteoarthritis (OA), a prevalent degenerative joint disorder accompanied by progressive cartilage degradation and pathological microenvironment alterations, remains a significant therapeutic challenge in clinical orthopedics. To tackle these problems, we developed an RGD-modified hyaluronic acid methacryloyl (HAMA) hydrogel co-loaded with cartilaginous inducer Kartogenin (KGN) and anti-aging protein Klotho (HAMA-RGD@KGN/Klotho, HRKK). Our bioactive multifunctional hydrogel system demonstrated excellent therapeutic potential to ameliorate OA-associated pathological conditions and promote cartilage regeneration. In vitro analyses revealed that the HRKK hydrogel effectively attenuated oxidative stress through reactive oxygen species (ROS) scavenging while modulating macrophage polarization toward anti-inflammatory phenotypes, creating a protective microenvironment for chondrocyte survival and functional maintenance. Besides, the engineered hydrogel could recruit endogenous bone marrow mesenchymal stem cells (BMSCs) and preserve their chondrogenic differentiation ability under an inflammatory environment. Transcriptomic profiling of chondrocytes and macrophages further provided mechanistic insights into hydrogel-mediated cartilage homeostasis maintenance and immunoregulation. In vivo validation using a rat cartilage defect model indicated that the HRKK hydrogel successfully established a regenerative niche, through sequential Klotho and KGN delivery, and facilitated structural cartilage restoration. This biomaterial-based strategy provides a promising clinical potential for preventing OA progression and achieving durable cartilage regeneration.