August 4, 2009

Researchers Grow Replacement Teeth In Lab Mice

A Japanese study published on Monday showed that researchers have successfully implanted bioengineered seed-like tissue into the jaws of mice, growing new teeth for the rodents, AFP reported.

Experts say the new technique could some day be used to replace other organs, according to the study published in the Proceedings of the National Academy of Sciences.

In the past, biologists have successfully cultivated limited tissue in a laboratory and successfully transplanted it into animals, but the new research explored ways to grow a three-dimensional organ in place, starting with teeth.

The research team, led by Etsuko Ikeda of the Tokyo University of Science, developed a bioengineered tooth germ, which is a seed-like tissue containing the cells and instructions necessary to form a tooth, and transplanted the germ into the jawbones of mice.

The germs then regularly grew into replacement teeth.

The team was able to grow the teeth in gums that had previously held milk and adult teeth. After successfully repeating the procedure on multiple occasions, the researchers were able to grow teeth hard enough to chew food.

By tracking the gene expression in the engineered tooth "germ" with a fluorescent protein, the team found that genes that were normally activated in tooth development were also active during growth of the engineered replacement.

Professor Takashi Tsuji of the Tokyo University of Science and one of the study's authors said the research provides the first evidence of a successful replacement of an entire and fully functioning organ in an adult body through the transplantation of bioengineered organ germ, reconstituted by single cell manipulation in vitro.

"The method could provide a model for future organ replacement therapy," he added.

The technique may one day be used to develop fully functioning bioengineered organs that can replace lost or damaged organs following disease, injury or aging.


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