Abstract:

BACKGROUND: Because urokinase has a short half-life, and has a sustained large dose, resulting in innegligible complications, it is necessary to develop slow-release thrombolytic drugs.  
OBJECTIVE: To study the characterization of urokinase chitosan nanoparticles.
METHODS: The nanoparticles were prepared via the self-assembly of chitosan and sodium tripolyphosphate. The morphololy was observed by transmission electron microscopy (TEM). Particle size was measured with particle size instrument. The encapsulation efficiency was tested by ELISA Reader. Drug loading efficiency was measured by the way of weighing lyophilized powder. Release characteristics of the nanoparticles were investigated both in vitro and in vivo.
RESULTS AND CONCLUSION: When the mass ratio of chitosan, sodium tripolyphosphate, and urokinas was 7:1:1, the solution was stable, the nanoparticle size was small, and drug encapsulation efficiency and loading efficiency were appropriate. When the highest encapsulation efficiency was 94.8%, the drug loading efficiency was 14.5% and mean diameter was 236 nm. TEM displayed that the morphology of nanoparticles was spherical and regular. The nanoparticles had better sustained-release properties, avoided the direct effect of digestive enzymes, and prolonged the half-life of urokinase to maintain a long-term activity in vivo.