(Agencies)
Updated: 2008-02-02 09:37

HELSINKI -- Scientists in Finland said they had replaced a 65-year-old patient's upper jaw with a bone transplant cultivated from stem cells isolated from his own fatty tissue and grown inside his abdomen.

An undated microscopic view of undifferentiated human embryonic stem cells. [Agencies]

Researchers said on Friday the breakthrough opened up new ways to treat severe tissue damage and made the prospect of custom-made living spare parts for humans a step closer to reality.

"There have been a couple of similar-sounding procedures before, but these didn't use the patient's own stem cells that were first cultured and expanded in laboratory and differentiated into bone tissue," said Riitta Suuronen of the Regea Institute of Regenerative Medicine, part of the University of Tampere.

She told a news conference the patient was recovering more quickly than he would have if he had received a bone graft from his leg.

"From the outside nobody would be able to tell he has been through such a procedure," she said.

She added, the team used no materials from animals -- preventing the risk of transmitting viruses than can be hidden in an animal's DNA, and followed European Union guidelines.

Stem cells are the body's master cells and they can be found throughout the blood and tissues. Researchers have recently found that fat contains stem cells which can be directed to form a variety of different tissues.

Using a patient's own stem cells provides a tailor-made transplant that the body should not reject.

Suuronen and her colleagues -- the project was run jointly with the Helsinki University Central Hospital -- isolated stem cells from the patient's fat and grew them for two weeks in a specially formulated nutritious soup that included the patient's own blood serum.

In this case they identified and pulled out cells called mesenchymal stem cells -- immature cells than can give rise to bone, muscle or blood vessels.

When they had enough cells to work with, they attached them to a scaffold made out of a calcium phosphate biomaterial and then put it inside the patient's abdomen to grow for nine months. The cells turned into a variety of tissues and even produced blood vessels, the researchers said.

The block was later transplanted into the patient's head and connected to the skull bone using screws and microsurgery to connect arteries and veins to the vessels of the neck.

The patient's upper jaw had previously been removed due to a benign tumor and he was unable to eat or speak without the use of a removable prosthesis.

Suuronen said her team had submitted a report on the procedure to a medical journal to be reviewed.