Lyophilized platelets: fifty years in the making.

Area of Science:

• Biomedical Engineering
• Hematology
• Biotechnology

Background:

• Efforts since the 1950s to freeze-dry platelets for hemostasis faced challenges with structural integrity and functionality.
• Previous methods using cross-linking agents preserved structure but were thought to eliminate platelet function.
• Early research demonstrated that fixed, freeze-dried platelets could agglutinate with ristocetin, indicating partial function.

Purpose of the Study:

• To refine the fixation process for freeze-dried platelets to retain essential hemostatic properties.
• To develop a stable, infusible hemostatic agent for treating bleeding patients.
• To create a potentially sterile cellular transfusion product.

Main Methods:

• Refinement of fixation techniques for platelets prior to freeze-drying (lyophilization).
• Evaluation of hemostatic function in various animal models with induced bleeding or platelet deficits.
• Assessment of the virucidal and bactericidal efficacy of the fixation and freeze-drying process.

Main Results:

• Developed fixed and freeze-dried platelets that retain fundamental hemostatic properties.
• Demonstrated correction of bleeding times in thrombocytopenic rabbits, canine cardiopulmonary bypass models, and porcine trauma models.
• The fixation process effectively eliminated spiked viruses and bacteria, suggesting a sterile product.

Conclusions:

• The refined fixation and freeze-drying process yields platelets with significant hemostatic capabilities.
• This technology offers a stable, potentially sterile cellular product for hemorrhage control.
• The development paves the way for clinical trials of Stasix, a pharmaceutical preparation for bleeding disorders.