Abstract:
Thrombotic diseases have led to seriously threat to human health. In recent years, the development goal of thrombolytic drugs have obtained new thrombolytic agents with good thrombolytic effect and highly drug safety. Upon using ferritin as the carrier, thrombolytic protein nanoparticles were constructed by modifying human ferritin H-chain protein (FTH1) with the low molecular weight single chain urokinase-type plasminogen activator which can be activated by thrombin (T-uPA). T-uPA was modified at the N terminus and C terminus of FTH1, respectively, using genetic engineering,
in vitro mixed renaturation technology and so on. It was found that only the T-uPA modified at the FTH1 (FTH1-T-uPA) could be folded correctly and assembled into the FTH1/FTH1-T-uPA. A series of characterizations showed that the FTH1 and FTH1-T-uPA subunits were successfully folded and assembled into the characteristic cages of ferritin. The FTH1/FTH1-T-uPA was obtained in the shape of spherical particles with a diameter of 13.41 nm and presented a very narrow size distribution in solution with a hydrodynamic diameter of 24.2 nm. Importantly, the T-uPA molecules of FTH1-T-uPA could be successfully activated by thrombin and had excellent fibrinolytic activity (1 200 IU/mg). The FTH1/FTH1-T-uPA could achieve comparable thrombolytic effects with the commercial urokinase, and showed much better safety
in vitro. This study shows that T-uPA can be successfully modified on the surface of ferritin and provide the methods for designing targeted drug loading system on the basis of ferritin nanoparticles.