Scientists in Hong Kong have developed the world’s first nasal spray to protect brain cells immediately following a stroke , an advance they claim could lead to a new “emergency rescue tool”. Stroke is one of the leading causes of death and disability, imposing an annual burden exceeding $890bn on healthcare systems worldwide. Current treatment for stroke begins after hospital admission and involves the use of clot-breaking drugs and reperfusion therapies designed to restore blood flow through arteries going to the brain. As the window for effective intervention is extremely narrow, however, more than 85 per cent of the patients are unable to receive timely treatment. Many drugs targeting the brain in clinical trials also fail as they cannot cross the organ’s protective barrier to keep away infectious germs from the blood. So developing timely interventions that are effective and safe within the “golden therapeutic window” remains key.…