Freeze-Dried Platelets Reduce Blood Brain Barrier Permeability and Intercranial Hemorrhage in Mice with Traumatic Brain Injury

Traumatic brain injury (TBI) is fatal in >30% of cases. While plasma transfusions have been shown to help reduce TBI mortality, little is known about the benefit of platelets and their derivatives. In a recent study, researchers explored the use of freeze-dried platelets, naturally rich in an angioprotein-1 (a potent vascular stabilizer), in mice with TBI. In cell cultures, freeze-dried platelets reduced the blood brain barrier (BBB) permeability in a dose-dependent manner in both endothelial monolayers and BBB organoids. In mice with TBI, transfused freeze-dried platelets were localized to the brain and reduced BBB permeability, whereas standard platelets and saline did not. In addition, transfused freeze-dried platelets preserved the microvascular structure in the brain, maintained capillary blood flow velocities, and attenuated intercranial hemorrhage compared to brains of control mice with TBI. Transfused freeze-dried platelets also attenuated neuroinflammation in mice with TBI; freeze-dried platelets reduced the activation of microglia, reduced macrophage infiltration, and attenuated astrocytosis. A pathway central to endothelial stability—the Tie2/angioprotein-1 pathway—was found to play a vital role in the effects of freeze-dried platelets in TBI in mice since inhibition of Tie2 worsened BBB permeability. Further research on the effectiveness of freeze-dried platelets is needed for treating TBI.

References:

1. Trivedi A, Miyazawa B, Zhang H, Qiu L, et al. A dried platelet-derived biologic for blood-brain barrier repair and hemorrhage control after TBI in mice. Blood. 2026 Jun 25;147(26):3231-3247. doi: 10.1182/blood.2025031826. PMID: 41843452.
2. Stolla M. From bench to broken brains: freeze-dried platelets. Blood. 2026 Jun 25;147(26):3132-3133. doi: 10.1182/blood.2026033837. PMID: 42348228.