Thrombolysis using liposomal-encapsulated streptokinase: an in vitro study

Area of Science:

• Biochemistry
• Pharmacology
• Materials Science

Background:

• Streptokinase (SK) is a potent plasminogen activator used in thrombolysis.
• SK's efficacy can be limited by plasma components, leading to reduced activity.
• Liposomes offer a potential delivery system to protect therapeutic agents.

Purpose of the Study:

• To evaluate the clot-lysing ability of SK encapsulated in liposomes.
• To assess the stability and activity of liposomal-encapsulated streptokinase (LESK) in plasma.
• To compare the thrombolytic potential of LESK versus free SK.

Main Methods:

• SK was encapsulated in large unilamellar phospholipid vesicles (liposomes).
• Activity of free SK and LESK was measured in Tris-buffered saline and platelet-poor plasma (PPP) at varying temperatures.
• Clot-dissolving time (CDT) was determined by measuring pressure drop during plasma filtration through membrane-bound thrombi.

Main Results:

• Liposome encapsulation retained approximately 30% of SK's original activity.
• LESK showed minimal activity loss in buffer over 24 hours at 4 and 23°C.
• While both free SK and LESK activities decreased in PPP at 37°C, LESK retained significantly higher activity.
• LESK demonstrated a more preserved clot-dissolving ability compared to free SK after incubation in PPP.

Conclusions:

• Liposome encapsulation effectively protects streptokinase from degradation in plasma.
• LESK exhibits enhanced stability and preserved thrombolytic potential compared to unencapsulated SK.
• This liposomal delivery system represents a promising strategy for improving SK-based thrombolytic therapy.