Feeder cell sources and feeder-free methods for human ips cell culture

Induced pluripotent stem cells (iPSCs) hold great promise for regenerative medicine and disease modeling. The original methods to grow human iPSCs utilized methods developed for human embryonic cells (ESCs), in which mitotically inactivated mouse-derived fibroblasts are mainly used as a feeder cell layer to maintain the undifferentiated status of pluripotent stem cells. However, these methods still require further consideration to facilitate cell expansion and to maintain the undifferentiated state of human iPSCs and/or ESCs for a longer period of time. In addition, the use of animal-derived feeders should be avoided for eventual clinical application of iPSC therapies. Therefore, human-derived feeder culture systems or feeder-free culture systems are currently being developed to prevent exposure to animal pathogens. In this review, existing mouse and human feeder culture systems for human ESCs and iPSCs are first introduced, and then previously reported feeder-free culture methods using extracellular matrix-associated products or synthetic biomaterials are outlined to discuss an appropriate culture system for clinical application of iPSCs.