Alzheimer's disease is a neurodegenerative disorder characterized by cerebrovascular and neuronal dysfunctions leading to a progressive decline in cognitive functions. We conducted behavioral studies to determine whether endothelin antagonists are able to improve the impairment of learning and memory in an animal model of Alzheimer's disease. We found that specific endothelin ETA receptor antagonists significantly improved the memory deficit. On the other hand, nonspecific endothelin ETA/ETB receptor antagonist did not produce any improvement in memory deficit. It is possible that endothelin ETB receptor antagonism is producing more harm than good. Hence we thought of an idea to determine the effect of an ETB receptor agonist on memory deficit. Our preliminary studies show that endothelin ETB receptor agonist, IRL-1620 significantly reversed impairment of learning and memory and oxidative stress parameters in an animal model of Alzheimer's disease. We are therefore interested in developing nanocarrier formulations of IRL-1620 that can selectively target its delivery to the brain for the treatment of Alzheimer's disease.