Application of induced pluripotent stem cells in generation of a tissue-engineered tooth-like structure.

Stem cells, such as adult stem cells or embryonic stem cells, are the most important seed cells employed in tooth tissue engineering. Even though dental-derived stem cells are a good source of seed cells for such procedures, they are not often used in clinical applications because of the limited supply. Induced pluripotent stem (iPS) cells, with their high proliferation and differentiation ability, are now considered a promising alternative. The objectives of this study were to assess the role of iPS cells in tooth tissue engineering. We used real-time polymerase chain reaction to confirm that mouse iPS (miPS) cells can be induced to express both odontogenic and osteogenic gene profiles. We then established a tooth germ model and transplanted the recombinant tooth germ into a mouse subrenal capsule for 4 weeks to reproduce early-tooth organogenesis. After 4 weeks, hematoxylin and eosin staining results showed newly formed bone-like and dental pulp-like areas. Further immunohistochemical staining confirmed that osteopontin was present in the apical part of the tooth-like structure. These results demonstrate that miPS cells have the potential to differentiate into odontogenic cells, confirming that they could be a new source of seed cells for use in tooth tissue engineering.