image: HKUMed has developed the world’s first nasal spray as prehospital emergency aid for ischemic stroke. The project was led by Professor Aviva Chow Shing-fung (right) from the Department of Pharmacology and Pharmacy at HKUMed, and Dr Shao Zitong from the InnoHK Advanced Biomedical Instrumentation Centre.
Credit: The University of Hong Kong
A research team from 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), has developed the world’s first ‘NanoPowder nasal spray’. This innovation successfully overcomes the challenge of crossing the blood-brain barrier (BBB), enabling the delivery of medication to the brain without the need for injections or surgery. When used promptly at the early onset of stroke, the nasal spray provides prehospital emergency treatment, helping to save time, thus protecting brain cells and reducing complications. In the long term, it has the potential to become a community-based emergency rescue tool.
This innovative prehospital emergency strategy is expected to substantially increase stroke survival rates and neurological recovery, representing a significant advancement in the treatment of brain diseases globally. The innovation was awarded the ‘Special Grand Prize – Prize of the Chinese Delegation’ and ‘Gold Medal with Congratulations of the Jury’ at the 51st International Exhibition of Inventions Geneva. It was also a winning project in HKUMedXelerate 2025 – an innovation challenge for transformative healthcare technologies.
Nasal spray: quick‑response, portable and easy to use
Ischemic stroke has long been the second cause of death and disability worldwide, imposing an annual global burden exceeding US$890 billion on healthcare systems and societies. Current standard treatments focus on reperfusion therapies, including intravenous thrombolytics and mechanical thrombectomy. However, the therapeutic window for effective intervention is exceedingly narrow. When combined with uneven access to medical resources, stringent eligibility criteria and the treatment-related risks, more than 85% of patients are unable to receive timely treatment. Even when treatment is successful, over half fail to achieve optimal functional recovery. Therefore, providing an intervention that is timely, effective and safe within the ‘golden therapeutic window’ remains a key challenge for the international medical community.
The research team spent over a decade developing the ‘Nano-in-Micron’ technology platform and subsequently used it to create the ‘NanoPowder nasal spray’. Professor Aviva Chow Shing-fung, Associate Professor in the Department of Pharmacology and Pharmacy at HKUMed and Co-Principal Investigator at the ABIC, said, ‘The nasal spray is characterised by its quick response, portability, and user-friendliness. It allows patients to receive early protection en route to hospital or even within the community, significantly slowing the death of brain cells under ischemic conditions and effectively preserving still-viable brain tissues, thereby buying valuable time for subsequent treatments.’
Micron-sized powder technology overcomes the blood-brain barrier
Professor Aviva Chow Shing-fung explained, ‘The failure rate of drug candidates targeting the central nervous system in clinical trials exceeds 90%, largely because these drugs cannot cross the BBB and thus fail to reach the brain to exert their therapeutic effects.’ To address this challenge, the research team encapsulated neuroprotective agents within nanoparticles and used particle engineering techniques to process them into inhalable micron-sized powders.
The nasal spray operates through four key steps: inhalation, deposition, de-agglomeration and delivery. The micron-sized powder is inhaled into the nasal cavity, where it effectively deposits in the target area. Upon contact with nasal mucus, the powders rapidly de-agglomerate into nanoparticles, which then travel along the nose-to-brain pathway, bypassing the BBB to deliver the drug directly to the brain. This design significantly enhances drug delivery efficiency and onset speed, offering a breakthrough solution for prehospital emergency treatment of ischemic stroke.
Ischemic infarct reduced by over 80%
Preclinical animal studies have demonstrated that administering the nasal spray within 30 minutes of stroke onset can reduce ischemic infarction by more than 80%, while effectively protecting neurological and motor functions. The study suggests that the medication may mitigate brain inflammation, prevent cell apoptosis, and preserve the integrity of the BBB, thereby providing comprehensive protection for brain tissues and potentially extending the time available for treatment.
Dr Shao Zitong, Postdoctoral Fellow at the ABIC, emphasised that this approach is not intended to replace existing hospital treatments but to serve as an urgent, prehospital support measure. Its goal is to work in tandem with current medical systems by providing early intervention to reduce the extent of brain damage and lower the risk of death and severe disability. Dr Shao stated, ‘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.’
Expanding global applications for neurological diseases
The NanoPowder nasal spray has demonstrated safety and efficacy through cell and animal experiments. The next steps involve advancing toxicology studies and clinical trials, with the aim of making this nasal spray accessible in pharmacies and communities as an emergency first-aid product, becoming the first line of defence for stroke patients. The research team is actively collecting feedback from emergency physicians and neurologists to ensure the invention aligns with real-world treatment protocols.
The ‘Nano-in-Micron’ technology platform can also be applied to deliver small molecule drugs, traditional Chinese medicine and biologics. Additionally, it has the potential to treat a range of neurodegenerative disorders, such as Alzheimer’s disease, motor neuron diseases, and cerebral infectious diseases such as meningitis.
About the research team
The research project was led by Professor Aviva Chow Shing-fung, Associate Professor from the Department of Pharmacology and Pharmacy at HKUMed and Co-Principal Investigator at the ABIC, and Dr Shao Zitong, Postdoctoral Fellow at the ABIC.
Acknowledgements
The research project was supported by the InnoHK initiative of the Innovation and Technology Commission, the Government of the Hong Kong Special Administrative Region of the People’s Republic of China; the Innovation and Technology Support Programme (ITSP); Hong Kong-Shenzhen Innovation and Technology Park (SPIN@HSITP); the HKUMed Technology Transfer Unit; and the HKU Techno-Entrepreneurship Core on funding, infrastructure and industrial transfer.
Media enquiries
Please contact LKS Faculty of Medicine of The University of Hong Kong by email (medmedia@hku.hk).