Natural and synthetic materials for self-renewal, long-term maintenance, and differentiation of induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) have attracted considerable attention from the public, clinicians, and scientists since their discovery in 2006, and raised huge expectations for regenerative medicine. One of the distinctive features of iPSCs is their propensity to differentiate into the cells of three germ lines in vitro and in vivo. The human iPSCs can be used to study the mechanisms underlying a disease and to monitor the disease progression, for testing drugs in vitro, and for cell therapy, avoiding many ethical and immunologic concerns. This technology offers the potential to take an individual approach to each patient and allows a more accurate diagnosis and specifi c treatment. However, there are several obstacles that impede the use of iPSCs. The derivation of fully reprogrammed iPSCs is expensive, time-consuming, and demands meticulous attention to many details. The use of biomaterials could increase the effi cacy and safety while decreasing the cost of tissue engineering. The choice of a substrate utilized for iPSC culture is also important because cell-substrate contacts infl uence cellular behavior such as selfrenewal, expansion, and differentiation. This Progress Report aims to summarize the advantages and drawbacks of natural and synthetic biomaterials, and to evaluate their role for maintenance and differentiation of iPSCs