New Nasal Spray Enables Prehospital Neuroprotection in Ischemic Stroke

Many patients arrive outside the narrow window for thrombolysis or thrombectomy, resulting in lasting disability and high health system costs. Prehospital neuroprotection that stabilizes salvageable tissue could improve outcomes and streamline stroke pathways. To help address this challenge, researchers have developed a nasal spray intended to deliver neuroprotective therapy to the brain before hospital arrival.

The NanoPowder nasal spray was developed by the Department of Pharmacology and Pharmacy at the LKS Faculty of Medicine, the University of Hong Kong (HKUMed), in collaboration with the InnoHK Advanced Biomedical Instrumentation Centre (ABIC). The team built the product on a Nano‑in‑Micron platform engineered to overcome the blood‑brain barrier (BBB). The approach enables direct brain delivery without injections or surgery. The aim is rapid administration in the community or during transport to the emergency department.

The spray consists of inhalable micron‑sized powder that encapsulates neuroprotective agents within nanoparticles. After inhalation, particles deposit in the nasal cavity and rapidly de‑agglomerate in mucus into nanoparticles. These nanoparticles travel along the nose‑to‑brain pathway, bypassing the BBB to deliver drug directly to brain tissue. The design is intended to increase delivery efficiency and speed of onset.

In preclinical animal studies, administration within 30 minutes of stroke onset reduced ischemic infarction by more than 80% and preserved neurological and motor functions. The study suggests potential mitigation of brain inflammation, prevention of cell apoptosis, and maintenance of BBB integrity. The developers emphasize that the spray is not a replacement for in‑hospital reperfusion but a prehospital support to lower the extent of brain damage. Safety and efficacy have been demonstrated in cell and animal experiments.

Next steps include advancing toxicology studies and clinical trials, with the goal of future community availability as an emergency first‑aid product. The platform may also be applied to deliver small molecules, biologics, and traditional Chinese medicine for neurological and infectious conditions. The project received the Special Grand Prize—Prize of the Chinese Delegation and the Gold Medal with Congratulations of the Jury at the 51st International Exhibition of Inventions Geneva, and it won HKUMedXelerate 2025.

Stroke remains the second leading cause of death and disability worldwide, with an annual burden exceeding US$890 billion. Eligibility constraints, treatment risks, and uneven access mean that more than 85% of patients do not receive timely reperfusion. Even after successful treatment, over half do not achieve optimal functional recovery. A prehospital option that fits the “golden therapeutic window” is therefore a priority for stroke systems of care.

"After a stroke, every second matters. Even an additional ten minutes of brain protection might determine whether a patient can walk or speak in the future. The key breakthrough of this technology lies in shifting stroke treatment from the 'in-hospital' setting to the 'prehospital' stage, enabling neuroprotection rather than merely clot dissolution or thrombectomy," said Dr. Shao Zitong, Postdoctoral Fellow at the ABIC.

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LKS Faculty of Medicine, HKUMed