Phase‐Change Based Oxygen Carriers Improve Acute Cerebral Hypoxia

Stroke is the second leading cause of death worldwide, and hypoxia is a major crisis of the brain after stroke. Therefore, providing oxygen to the brain microenvironment can effectively protect neurons from damage caused by cerebral hypoxia. However, there is a lack of timely and effective means of oxygen delivery clinically to the brain for acute cerebral hypoxia. Here, a phase‐change based nano oxygen carrier is reported, which can undergo a phase change in response to increasing temperature in the brain, leading to oxygen release. The nano oxygen carrier demonstrate intracerebral oxygen delivery capacity and is able to release oxygen in the hypoxic and inflammatory region of the brain. In the acute ischemic stroke mouse model, the nano oxygen carrier can effectively reduce the area of cerebral infarction and decrease the level of inflammation triggered by cerebral hypoxia. By taking advantage of the increase in temperature during cerebral hypoxia, phase‐change oxygen carrier proposes a new intracerebral oxygen delivery strategy for reducing acute cerebral hypoxia. Acute cerebral hypoxia induces oxidative stress, mitochondrial dysfunction, and inflammation, leading to irreversible brain damage. Timely restoration of blood oxygen supply can reduce brain damage. The oxygen carrier with temperature phase change can release oxygen according to the temperature in the brain, improve hypoxia, protect brain tissue from hypoxic damage, and reduce the inflammatory response after hypoxia‐reperfusion.