Mouse gets lab-grown tooth transplant

A tooth grown from stem cells and successfully implanted into the jaw of a mouse has been hailed as a step towards the development of human organs grown from a patient's own cells.

In a world first, Professor Takashi Tsuji and his team from the Tokyo University of Science, Japan took stem cells programmed to become teeth from mouse embryos. These were implanted into an adult mouse's kidney, and after two months a perfect molar had developed.

The tooth had the vital bone and periodontal ligaments needed for attachment, and so the team transplanted it into another mouse's lower jawbone. Six weeks later, all the right blood and nerve connections had been made, allowing the bioengineered tooth to function as though it had grown naturally.

'The bioengineered teeth were fully functional... there was no trouble biting and eating food after transplantation', explained Dr Masamitsu Oshima, co-author of the study.

Donor organ transplantation provides a vital treatment in the replacement of dysfunctional organs due to disease, injury or ageing. The researchers have described their work as a 'substantial advance' in the quest to produce organs from a patient's own cells, which would avoid the issue of rejection which comes with donor transplantation.

However, growing teeth inside a human body is unfeasible and prevents the method from being applicable to human tooth replacement. 'At present, researchers worldwide do not have the method to culture three-dimensional organs in vitro [outside the body]', Professor Tsuji explained to Reuters.

International efforts have already developed skin and bladder tissue for transplantation from adult stem cells, but much more work is needed before complex organs can be produced. The Daily Mail reported the researchers as saying that it would be at least a decade before people can 'grow their own teeth'.

The findings were published in the journal PLoS One.