Lab-grown replacement teeth fill the gap

Takashi Tsuji at the Tokyo University of Science, Japan, and his colleagues took single-tooth mesenchymal and epithelial cells – the two cell types that develop into a tooth – from mouse embryos. They stimulated these cells to multiply before injecting them into a drop of collagen gel. Within days, the cells formed tooth buds – the early stage of normal tooth formation. The team then transplanted these tooth buds into cavities left after they had extracted teeth from adult mice. There, they developed into teeth with a normal structure and composition. The engineered teeth also developed a healthy blood supply, and nerve connections.

Previous approaches to regenerating teeth have involved growing them in the kidneys of mice before transplanting them into the mouths of other mice. “This study represents an important contribution to the field of tooth regeneration” because it demonstrates how teeth can be grown directly in the mouth, says Jeremy Mao, at the Columbia University College of Dental Medicine in New York, US. But Paul Sharpe at Kings College London, UK, notes that earlier studies have shown alternative methods of regenerating teeth directly in animals’ mouths. He says Tsuji’s approach is different from earlier methods because it involves culturing the cells in a collagen gel. But according to Sharpe, the advantage of using such a gel mixture remains unclear. Since mesenchymal and epithelial cells have the potential to develop into other organs and hair follicles, Tsuji hopes his method could eventually be applied more widely. “We hope to collaborate with dentists and clinicians in various fields to develop artificial organs for people,” he says.
Source: Nature Methods

New Scientist
March 6, 2007

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