It was learned from Tianjin University that Li Nan, professor of the School of Pharmacy of the Medical Department of Tianjin University, has developed a new streamlined zinc oxide chimeric injectable hydrogel, which has opened up a new path for the treatment of osteoarthritis and cartilage regeneration. The streamlined hydrogel has the dual characteristics of "smoothness during injection" and "firmness after implantation". The relevant research results were recently published in the international journal Nature Communications. This research focuses on the key problem of extracellular matrix homeostasis disorder in the treatment of osteoarthritis. The designed streamlined zinc oxide chimeric injectable hydrogel has matrix metalloproteinase response characteristics, and is equipped with miR-17-5p gene drug, which can achieve two-way regulation of extracellular matrix homeostasis. MiR-17-5p gene drug is a microRNA molecule with the function of regulating gene expression, which can effectively inhibit the overactive matrix metalloproteinases in osteoarthritis. "Matrix metalloproteinases are the key factor leading to excessive degradation of extracellular matrix. Compared with the traditional spherical structure chimeric hydrogel, the streamlined zinc oxide structure chimeric optimizes the rheological and mechanical properties of the hydrogel, giving the hydrogel a synergistic advantage of high mechanical strength and low flow viscosity." Li Nan introduced. The hydrogel exhibits a smooth property when injected, mainly due to the streamlined zinc oxide nanoparticles inside. These nanoparticles have a unique high curvature structure, which enables them to effectively reduce fluid resistance during injection. Specifically, the high curvature structure of streamlined zinc oxide reduces the viscosity of hydrogel during injection, enabling it to pass through the injection needle more smoothly, thus realizing rapid filling of irregular tissue defects. When the hydrogel is injected into the target site, the cross-linking reaction will occur quickly to form a more solid network structure. The hydrogen bond interaction between the streamlined zinc oxide nanoparticles with high specific surface area and the polymer chain further enhances this cross-linking, which makes the mechanical properties of the hydrogel significantly improved, can effectively resist external mechanical stress, and finally achieve the robustness after implantation. Experiments have shown that the streamlined structure significantly improves the transfection efficiency of miR-17-5p, providing a new approach for precise delivery of gene therapy. This design not only reduces the energy loss during the injection process, improves the fluidity of the gel, but also significantly enhances the support ability of the hydrogel in the tissue defect area, providing guarantee for long-term treatment effect and structural integrity. (New Society)