Neurological disorders such as Stroke, Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), Amyotrophic Lateral Sclerosis (ALS), and Spinal cord injuries (SCI) have inflicted millions of patients in US and even more patients worldwide. The medical and financial burdens are tremendous not only to the families but also to the entire society. Stroke is the leading cause of long-term disability in US, with nearly 800,000 people experience a stroke each year and seven million stroke survivors in total. Alzheimer’s disease is also rapidly growing in US and around the world, with 5.7 million patients in US and the number is continuously increasing significantly each year with growing aging population. The annual cost of care for Alzheimer’s patients in US is projected to be $277 billion in 2018 and over one trillion dollars by 2050.
Loss of functional neurons is the common feature of acute neural injuries and neurodegenerative diseases. The inability of neurons to replenish themselves brings the greatest challenge in the treatment of neurological disorders. The current therapeutic approaches are mostly trying to prevent or slow down the neuronal loss but cannot regenerate many new neurons once neurons are lost. Thus, there are no effective treatments for neurodegenerative diseases such as AD and ALS or neural injuries such as stroke. Developing a new technology to regenerate functional new neurons has been the long-time pursuit of the researchers in academics and industry.