The viability and coagulation function of storing platelets can be maintained in plasma without cryoprotectants at -80 °C.

Background: To prolong the storage period of platelets, dimethyl sulfoxide (DMSO) has been used for platelet cryopreservation at -80 °C to prevent cold storage lesions. Nevertheless, it is important to note that DMSO is a toxic chemical agent that may cause adverse effects and potential safety concerns for clinical applications. Therefore, many studies have attempted to reduce the DMSO concentration used for platelet cryopreservation. Based on our previous findings regarding the stability of platelets in platelet-rich plasma stored at -80 °C for 1 month, it is imperative to explore the cryopreservation of platelets in plasma. Objectives: This study aimed to evaluate the feasibility of storing apheresis platelets in plasma at -80 °C as a supplemental solution in the absence of cryoprotectants, such as DMSO. Methods: We used a comprehensive approach, analyzing platelet count, morphology, mitochondrial structure, and metabolomic and proteomic profiles to assess storage lesions. Results: Our findings revealed that platelets stored at -80 °C in plasma maintained a stable cell count and procoagulant function, comparable with those stored with DMSO. Proteomic analysis showed that the fundamental protein composition essential for platelet clotting function was largely preserved, while metabolomic analysis suggested that metabolism had a minimal impact on platelet homeostasis. Conclusion: These results demonstrate that storage in plasma at -80 °C effectively preserves platelet viability and functionality over a short period. This study highlights the potential for developing supplementary storage strategies as alternatives to conventional preservation methods, which could improve platelet availability in transfusion medicine.