For a variety of disorders, replacement cells must be available quickly, before the effects of disease and injury become irreparable, whether by ancillary cell loss or maladaptive circuit reconstruction. Depending upon the time window during which cells may be able to effectively integrate into the injured or diseased neural network, the ramp-up time between pluripotential cell deployment and the production of transplantable phenotypes of need may be problematic. This issue is especially concerning when autologous cell delivery is desired. Whereas iPSCs and their derivatives have the advantage of potential autologous use, the long time frames involved in producing iPSCs from somatic cells, and in then producing cell types of interest from those cells, can limit the disease targets for which their use is appropriate. For instance, any iPSC-based treatment of acute demyelinating injuries that might benefit from rapid introduction of OPCs would likely be hindered by the turn-around time of going from biopsied fibroblasts to iPSCs to transplantable OPCs, a sequence that currently spans well over a half-year.
