Platelets loaded with liposome-encapsulated thrombin have increased coagulability

Area of Science:

• Biomedical Engineering
• Hematology
• Nanotechnology

Background:

• Platelets are crucial for clot formation but transfusions have limited efficacy in severe hemorrhage.
• Existing platelet-mimicking nanoparticles lack essential platelet functions.
• Thrombin, a potent agonist, cannot be administered intravenously due to thrombosis risk.

Purpose of the Study:

• To enhance the coagulability of transfusable platelets by delivering thrombin ex vivo.
• To investigate the potential of liposomal encapsulation for targeted thrombin delivery to platelets.
• To improve platelet efficacy in treating severe hemorrhage and coagulopathy.

Main Methods:

• Thrombin was encapsulated into nanoliposomes and delivered to platelets ex vivo.
• Platelet coagulability was assessed via activation, clot contraction, time, and stability assays.
• Assays were conducted under compromised coagulation conditions (acidosis, antiplatelet drugs, hemophilia A, trauma-induced coagulopathy).

Main Results:

• Liposomal thrombin was successfully endocytosed and utilized by platelets ex vivo.
• Modified platelets exhibited increased sensitivity and responsiveness to agonists.
• Enhanced platelet function improved clotting time, even in models of impaired coagulation.

Conclusions:

• Ex vivo delivery of liposomal thrombin enhances multiple aspects of platelet function.
• This method improves platelet coagulability and clot formation.
• Liposomal thrombin-loaded platelets show promise for treating bleeding disorders and coagulopathy.