Enhancing thrombolysis through targeted delivery of urokinase by H₂O₂-responsive nanoparticles delivery system

Thrombotic diseases, such as stroke and myocardial infarction, represent significant threats to global health. Timely and safe thrombolysis is crucial in improving tissue ischemia and preventing thrombosis progression. Urokinase (UK) is a widely used thrombolytic agent, however, its clinical use is constrained by bleeding risks and other adverse effects. In this study, EGCG-Mn-Fuc nanoparticles with H₂O₂ responsiveness were successfully prepared. Urokinase was loaded into the nanomaterials via the direct assembly method, and the thrombolytic effect of these nanoparticles was investigated. The preparation process of the nanoparticles is straightforward, and the reaction conditions are relatively mild. The physical and chemical properties of the EGCG-Mn-Fuc nanoparticles were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), Ultraviolet and visible spectrum (UV-Vis) and X-ray photoelectron spectroscopy (XPS). In cell experiments, EGCG-Mn-Fuc nanoparticles showed low cytotoxicity and good biocompatibility. Furthermore, these nanoparticles effectively scavenged DPPH free radicals, attributing this capability primarily to their antioxidant properties. In vitro thrombolytic experiments showed that EGCG-Mn-Fuc nanoparticles intelligently responded to H₂O₂, releasing the loaded urokinase and exerting a thrombolytic effect. The microcapsules exhibited concentration-dependent thrombolytic effects, effectively dissolving thrombi in the presence of H₂O₂. Hemolysis and coagulation tests confirmed their good blood compatibility and anticoagulant properties. In addition, it is worth noting that the nanoparticle contains fucoidan that mimics P-selectin glycoprotein ligand-1(PSGL-1) and has a high affinity for activating P-selectin on the surface of platelets. Overall, the results of this study not only provide valuable experimental evidence and theoretical support for the application of EGCG-Mn-Fuc nanoparticles in the field of thrombolysis, but also establish a foundation for the biomedical application of drug carriers in this field.