Streamlined metal-based hydrogel facilitates stem cell differentiation, extracellular matrix homeostasis and cartilage repair in male rats

Dysregulation of extracellular matrix (ECM) homeostasis plays a pivotal role in the accelerated degradation of cartilage, presenting a notable challenge for effective osteoarthritis (OA) treatment and cartilage regeneration. In this study, we introduced an injectable hydrogel based on streamlined-zinc oxide (ZnO), which is responsive to matrix metallopeptidase (MMP), for the delivery of miR-17-5p. This approach aimed to address cartilage damage by regulating ECM homeostasis. The ZnO/miR-17-5p composite functions by releasing zinc ions to attract native bone marrow mesenchymal stem cells, thereby fostering ECM synthesis through the proliferation of new chondrocytes. Concurrently, sustained delivery of miR-17-5p targets enzymes responsible for matrix degradation, thereby mitigating the catabolic process. Notably, the unique structure of the streamlined ZnO nanoparticles is distinct from their conventional spherical counterparts, which not only optimizes the rheological and mechanical properties of the hydrogels, but also enhances the efficiency of miR-17-5p transfection. Our male rat model demonstrated that the combination of streamlined ZnO, MMP-responsive hydrogels, and miRNA-based therapy effectively managed the equilibrium between catabolism and anabolism within the ECM, presenting a fresh perspective in the realm of OA treatment.