Scientists in Hong Kong have developed the world’s first nasal spray designed to protect brain cells immediately after a stroke, an advance they describe as a potential “emergency rescue tool”. The spray, called Nanopowder, delivers brain-protective drugs directly to the brain via the nose, bypassing the blood-brain barrier.
Stroke remains one of the leading causes of death and disability worldwide, placing an annual burden of more than $890bn on healthcare systems. Current treatments, such as clot-busting drugs and reperfusion therapies, are only administered after hospital admission, and the narrow window for effective intervention means over 85 per cent of patients do not receive timely care.
Many central nervous system drugs fail in clinical trials because they cannot cross the blood-brain barrier, the protective shield that prevents germs and other substances from entering the brain. “The failure rate of drug candidates targeting the central nervous system in clinical trials exceeds 90 per cent, largely because these drugs cannot cross the blood-brain barrier,” said Aviva Chow Shing-fung from Hong Kong University.
The Nanopowder spray is inhaled into the nasal cavity, where it deposits in the target area and breaks into ultra-small nanoparticles. These particles travel along the nose-to-brain pathway, bypassing the barrier to deliver the drug directly to the brain. Research showed that administering the spray within 30 minutes of stroke onset reduced brain tissue death by over 80 per cent and protected neurological and movement functions.
“After a stroke, every second matters,” said Shao Zitong, a postdoctoral fellow at Hong Kong University. “Even an additional 10 minutes of brain protection might determine whether a patient can walk or speak in the future.” She said the key breakthrough is shifting treatment from the in-hospital setting to the prehospital stage, enabling neuroprotection rather than merely clot dissolution or thrombectomy.
The developers believe the spray could be a breakthrough for prehospital emergency care, offering early protection while patients are en route to hospital and buying valuable time for subsequent intervention. Further clinical testing is needed before the spray can be deployed in practice.
