Freeze-dried platelet therapy study shows promise to treat traumatic brain injuries

A platelet-derived product engineered for long-term storage has reduced haemorrhage, vascular leakage and inflammation in mouse models of traumatic brain injury, with findings that suggest a potential route to early intervention in the clinic

A freeze-dried blood product designed to remain stable for years in ambulances or remote emergency settings has shown promise as a treatment for traumatic brain injury (TBI), according to preclinical findings from researchers at University of California San Francisco, USA. The study has indicated that the therapy could address a longstanding gap in care for a condition that remains the leading cause of death for people in their forties and younger.

TBI involves both immediate mechanical damage and a delayed cascade of secondary injuries. In the acute phase, bleeding within the brain can often be an immediate threat to like. However, even after patients reach hospital, further complications can arise days later as the integrity of cerebral blood vessels deteriorates, which may lead to leakage, inflammation and swelling. This process – known as cerebral oedema – contributes substantially to mortality and long-term neurological impairment. Current treatment options remain limited with surgical decompression often the only available intervention which relieves pressure from within the skull.

The investigational product in the study – called ‘Thrombosomes’ – has been derived from human platelets that researchers have stabilised through a freeze-drying process by using the disaccharide ‘trehalose’. This process preserves functional components and, crucially, allows for storage at ambient conditions for long periods – expected to be up to five years. By contrast, fresh platelets when they are sourced from donors typically require refrigeration and have a shelf life of approximately seven days. Platelets are widely used clinically to manage haemorrhage, in the support of oncology patients or prevent bleeding during surgery, but they have not demonstrated sufficient efficacy in the treatment of TBI.

Efforts to preserve platelet function have been underway for more than three decades, against the backdrop of chronic global shortages of donor-derived platelets. Despite this sustained research focus, no preserved platelet product has yet secured regulatory approval for human use or have previously been positioned as a therapy for TBI.

In the present study, the research team evaluated Thrombosomes across a series of in vitro and in vivo models. Experiments on cultured vascular endothelial cells and three-dimensional organoid systems that mimic blood vessel architecture demonstrated that the product enhanced resistance to structural damage. In mouse models of TBI, administration of the therapy at either one hour or 24 hours post-injury reduced intracranial haemorrhage and limited vascular permeability. Treated animals also exhibited reduced neuroinflammation which is a key driver of cerebral oedema.

Mechanistic analysis suggested that the therapeutic effect may arise from a high concentration of proteins capable of activating receptors on endothelial cells. Activation of these pathways appeared to strengthen vascular integrity and reduce leakage. The authors proposed that this represents only part of a broader profile of biologically active molecules within the preparation, which may act in concert to stabilise injured tissue.

“In some cases, surgeons will remove part of the skull to relieve the pressure – but there’s no drug that effectively treats swelling – cerebral oedema – directly,” said Dr. Shibani Pati, director of the UCSF Center for Research in Transfusion Medicine and Cell Therapies and senior author of the study.

“We were excited to see how readily this product reinforced damaged blood vessels in the brain,” she said.

The findings have added to a growing body of evidence that platelets exert biological effects beyond their traditional role in clot formation. Platelets contain a diverse repertoire of signalling molecules, growth factors and structural proteins that influence vascular repair, inflammation and tissue regeneration. Concentration of these components within a stable formulation may therefore offer advantages beyond those of transfused platelets.

“Platelets carry many potent factors that go beyond clotting. In our mouse model of TBI, we saw hints that this product concentrates these factors [making] it more effective than [fresh blood transfusion] platelets themselves,” Pati added.

Although the results remain at an early stage, the prospect of a shelf-stable, field-deployable therapy has attracted interest, particularly in settings where rapid access to specialised neurosurgical care proves challenging. Military medicine, pre-hospital emergency services and rural healthcare systems may all benefit from an intervention that can stabilise vascular injury before patients reach definitive care.

Further studies will need to confirm safety, dosing parameters and efficacy in human populations. Nonetheless, the work has highlighted a potential shift in how clinicians might approach TBI, with emphasis on early pharmacological stabilisation of the neurovascular unit rather than reliance on surgical intervention.

For further reading please visit: 10.1182/blood.2025031826