Rodent teeth grow from stem cells
Mice have grown new teeth from stem cells implanted into the jawbone. Stem cell technology has been used before to produce tissues, but in a limited way. This is the first time a study has shown that a few cells can go on to produce a fully functioning organ.
The team began by removing the upper molars from five-week-old mice. They developed a seed-like bioengineered tooth tissue containing stem cells and the genetic instructions necessary to form a tooth, and transplanted the tissue into the jawbones of mice.
The implanted cells developed into fully formed teeth with an identical structure to normal teeth. They were hard enough to allow chewing and showed typical responses to pain, due to the development of an extensive network of nerve fibres. Gene activation was tracked using a green fluorescent protein and was seen to be identical to that in normal tooth development.
Further tests will look at side effects of this technique, and whether it could work in humans. However, it is an interesting starting point in organ replacement techniques, showing that stem cells can become whole organs.