Alzheimer's disease and Parkinson's are common age-related diseases that affect millions of people across the world. According to estimates in 2020 around 5.8 million Americans were diagnosed with Alzheimer's disease 1 million with Parkinson's disease 914000 with multiple sclerosis and 63000 with motor neuron disease. These diseases are the result of degeneration and death of the nerve cells in the brain and nervous system. The changes are associated with the breakdown of what is called the blood-brain barrier -- a border of cells that keeps the wrong kind of molecules in the bloodstream from entering the brain and damaging it.