Sunday, May 13, 2007

No more gaps with home-grown teeth

HERE'S something to smile about: replacement teeth have been grown from scratch and implanted into the mouths of adult mice. A similar technique might one day replace missing teeth in humans.
Takashi Tsuji at the Tokyo University of Science in Japan and his colleagues extracted single tooth mesenchymal and epithelial cells - the two cell types that develop into a tooth - from mouse embryos. They persuaded these cells to multiply and injected them into a drop of collagen gel. Within days, the cells formed tooth buds, the early stage of normal tooth formation.
The team extracted teeth from adult mice and transplanted the tooth buds into the cavities, where they developed into teeth with a normal structure and composition. The engineered teeth also developed a healthy blood supply and nerve connections (Nature Methods, DOI: 10.1038/NMETH1012).
Other researchers have previously grown intact teeth from engineered tooth buds implanted in the kidneys of mice. They stopped short of showing that engineered buds could develop into teeth in the jaw (New Scientist, 26 June 2004, p 13).
The cells in Tsuji's study were taken from embryos, meaning the technique would be difficult apply to humans for now. His team is now planning to look for adult cells, such as epithelial or mesynchymal stem cells, that could be used instead.
From issue 2592 of New Scientist magazine, 24 February 2007, page 18

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