Scientists in Hong Kong have developed the world's first nasal spray capable of protecting brain cells immediately after a stroke, a development they describe as potentially creating a new "emergency rescue tool".
Stroke is one of the leading causes of death and disability worldwide, and health systems around the world bear an annual burden of over $890 billion.
Current stroke treatment begins after the patient is admitted to the hospital and relies on the use of clot-dissolving drugs and reperfusion therapies designed to restore blood flow through the arteries leading to the brain.
However, the window for effective intervention is extremely narrow, meaning that more than 85% of patients are unable to receive treatment in time. Furthermore, many drugs targeting the brain fail in clinical trials because they cannot cross the blood-brain barrier, which protects the organ from germs. Therefore, developing effective and safe interventions within the "golden therapeutic window" remains a key objective.
Aviva Chao-Sheng Fung from the University of Hong Kong explained: "The failure rate of candidate drugs targeting the central nervous system in clinical trials exceeds 90%, largely because these drugs cannot cross the blood-brain barrier and therefore fail to reach the brain to exert their therapeutic effects."
To overcome this problem, scientists developed a nasal spray called "Nanopowder" containing brain-protective drugs as the active ingredient, which are developed into ultra-fine, inhalable powders. The spray is inhaled into the nasal cavity, where it effectively settles in the targeted area and breaks down into nanoparticles. These tiny particles then travel from the nose to the brain, crossing the blood-brain barrier to deliver the drug directly to the organ, according to the scientists.
Scientists say the nasal spray provides early protection on the way to the hospital, significantly slowing the death of brain cells immediately after a stroke, buying valuable time for subsequent interventions, and could be a revolutionary solution for emergency stroke treatment before reaching the hospital.
Researchers found that administering a nasal spray within 30 minutes of stroke onset can reduce brain tissue death by more than 80% and protect neurological function and body movement. The spray can also reduce inflammation, prevent cell death, and maintain the integrity of the blood-brain barrier, potentially extending the time available for treatment.
“After a stroke, every second counts,” said Shao Zhitong, a postdoctoral fellow at the University of Hong Kong. “Even 10 extra minutes of brain protection can determine whether a patient will be able to walk or talk in the future.” She explained that “the key breakthrough of this technique is shifting stroke treatment from an ‘inpatient’ to a ‘pre-hospital’ approach, allowing us to protect nerve cells instead of simply dissolving or removing the clot.”
