Study leaders: Prof Aviva Shing-Fung Chow (right) and Dr Zitong Shao (left)In collaboration with the InnoHK Advanced Biomedical Instrumentation Centre (ABIC), the research team had spent over a decade developing the ‘Nano-in-Micron’ technology platform and subsequently used it to create the NanoPowder nasal spray. The innovation won 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.
Preclinical animal studies have demonstrated that administering the nasal spray within 30 minutes of stroke onset can reduce ischaemic infarction by >80 percent, while effectively protecting neurological and motor functions. The findings suggest that the medication may mitigate brain inflammation, prevent cell apoptosis, and preserve the integrity of the blood-brain barrier (BBB), thereby providing comprehensive protection for brain tissues, reducing complications, and potentially extending the time available for subsequent treatments.
“The nasal spray is characterized by its quick response delivery, portability, and user-friendliness,” reported leader of the study, Professor Aviva Shing-Fung Chow of the Department of Pharmacology and Pharmacy, HKU. “It provides patients with early protection en route to hospital or even within the community, significantly slowing brain cell death under ischaemic conditions, and effectively preserving still-viable brain tissues.”
“The failure rate of drug candidates targeting the central nervous system exceeds 90 percent in clinical trials, largely because these drugs cannot cross the BBB and thus fail to reach the brain to exert their therapeutic effects,” explained Chow. “To address this challenge, we encapsulated neuroprotective agents within nanoparticles and processed them with particle engineering techniques to develop inhalable micron-sized powder.”
The micron-sized powder is then administered via a nasal spray device to work through four key steps: inhalation, deposition, de-agglomeration and delivery. When inhaled into the nasal cavity and deposited onto the nasal mucosa, the powder rapidly de-agglomerates 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 ischaemic stroke.
“This approach is not intended to replace existing hospital treatments. Instead, it is intended 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,” emphasized the study’s co-leader, Dr Zitong Shao of ABIC.
“After a stroke, every second matters. An additional 10 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,” she added.