Preparation and characterization of tissue plasminogen activator-loaded liposomes

Liposomes have drawn a lot of interest as pharmaceutical carriers for thrombolytic enzymes. Tissue plasminogen activator (tPA) is a thrombolytic drug used to treat cardiovascular disorders. Clinical efficacy of tPA is limited by its short half-life, hemorrhagic side effects and poor penetration into large blood clots. Using its liposomal form can reduce such effects and improve thrombolytic activity. The aim of this work is to study the effect of the composition of tPA-loaded liposomes on their physicochemical characteristics, such as size, zeta-potential, entrapment efficiency, proteolytic activity and in vitro release. It was found that prepared liposomes were relatively stable, no aggregation was observed during the storage at 4 degrees C. Lipid compositions had a minor influence on the incorporation efficiency and a significant effect on the percentage of tPA released per time as well as its proteolytic activity. Developed liposomal form of tissue plasminogen activator can be used for treatment cardiovascular diseases due to its small size, stability, high entrapment efficiency and slow rate of drug release.