Reperfusion injury occurs when blood is returned to the brain after a period of time where is has been restricted, often due to stroke or heart attack. The absence of oxygen and nutrients from blood often creates a condition where the restoration of circulation will result in inflammation and oxidative damage to the brain. Researchers at the University of Nebraska have developed a method in which powerful antioxidants, such as superoxidase dismutase (SOD) and catalase (CAT), are encapsulated by biodegradable nanoparticles that can readily cross the blood brain barrier. When SOD-nanoparticles were injected at the time of reperfusion, animals demonstrated improved neurological behavior and a 70% reduction in the total infarct volume. This indicates that the use of SOD-nanoparticles would be highly beneficial in use with patients that undergo reperfusion.