Bioengineered stem cells in neural development and neurodegeneration research

•Induced pluripotent stem cells, induced neurons and induced neural stem cells can be generated from human fibroblasts.•Bioengineered stem cells form three-dimensional brain structures and follow guidance cues.•Human induced pluripotent stem cells and neurons can be used to model diseases in neural development and neurodegeneration.•Bioengineered stem cell models can be used for development of therapies.

The recent discovery of a simple method for making induced pluripotent stem cells (iPSC) from human somatic cells was a major scientific advancement that opened the way for many promising new developments in the study of developmental and degenerative diseases. iPSC have already been used to model many different types of neurological diseases, including autism, schizophrenia, Alzheimer's disease and Parkinson's disease. Because of their pluripotent property, iPSC offer the possibility of modeling human development in vitro. Their differentiation seems to follow the developmental timeline and obeys environmental cues. Clinically relevant phenotypes of neurodegenerative pathologies have also been observed using iPSC derived human neuronal cultures. Options for treatment are still some way off. Although some early research in mouse models has been encouraging, major obstacles remain for neural stem cell (NSC) transplantation therapy. However, iPSC now offer the prospect of an unlimited amount of human neurons or astrocytes for drug testing. The aim of this review is to summarize the recent progress in modeling neural development and neurological diseases using iPSC and to describe their applications for aging research and personalized medicine.