Freeze-dried platelets promote clot formation, attenuate endothelial cell permeability, and decrease pulmonary...

Area of Science:

• Biomedical Engineering
• Hematology
• Trauma Research

Background:

• Hemorrhagic shock (HS) and trauma compromise endothelial barriers, leading to inflammation and clotting issues.
• Fresh human platelets (Plts) and their extracellular vesicles can mitigate vascular leak in injury models.
• This study investigates freeze-dried platelets (FDPlts) for their potential to reduce pulmonary vascular permeability, inflammation, and promote clotting in HS.

Purpose of the Study:

• To evaluate the efficacy of freeze-dried platelets (FDPlts) in a murine model of hemorrhagic shock (HS).
• To assess FDPlts' ability to attenuate pulmonary vascular permeability, decrease inflammation, and promote clotting.
• To compare the effects of FDPlts with fresh human platelets and whole blood resuscitation.

Main Methods:

• Characterized human FDPlts using in vitro assays for marker expression, aggregation, coagulation, and endothelial cell permeability.
• Assessed FDPlt incorporation into clots in a mouse cremaster muscle intravital injury model.
• Compared outcomes in HS mice resuscitated with lactated Ringer (LR) solution, FDPlts, fresh human Plts, or murine whole blood (WB) against sham controls.

Main Results:

• FDPlts retained platelet-specific markers and functionality, incorporating into clots similarly to fresh Plts.
• HS mice resuscitated with LR showed significantly increased pulmonary vascular permeability.
• FDPlts and WB attenuated vascular permeability in HS mice, while fresh human Plts did not show a significant effect.

Conclusions:

• FDPlts contribute to clot formation and attenuate vascular permeability in vitro and in vivo.
• FDPlts represent a potential alternative to fresh platelets for modulating hemostasis and endotheliopathy in HS.
• Resuscitation with FDPlts or WB, but not fresh human Plts, attenuated vascular permeability post-HS.