Use of differentiated pluripotent stem cells as replacement therapy for treating disease

Patient-derived pluripotent stem cells (PSCs) hold promise in the treatment of injury and disease. An ever-increasing number of specific cell types can be generated from PSCs, but technical challenges remain in applying these cells in the clinic. Fox et al. review the challenges in attaining this goal. These include gene modification, cell rejection, and delivery and localization issues involved in transplantation of cells for the treatment of diabetes and disorders of the blood, liver, heart, and brain. Science , this issue 10.1126/science.1247391 Pluripotent stem cells (PSCs) directed to various cell fates holds promise as source material for treating numerous disorders. The availability of precisely differentiated PSC-derived cells will dramatically affect blood component and hematopoietic stem cell therapies and should facilitate treatment of diabetes, some forms of liver disease and neurologic disorders, retinal diseases, and possibly heart disease. Although an unlimited supply of specific cell types is needed, other barriers must be overcome. This review of the state of cell therapies highlights important challenges. Successful cell transplantation will require optimizing the best cell type and site for engraftment, overcoming limitations to cell migration and tissue integration, and occasionally needing to control immunologic reactivity, as well as a number of other challenges. Collaboration among scientists, clinicians, and industry is critical for generating new stem cell–based therapies.