From news.bbc.co.uk
Scientists have created part of the jaw joint in the lab using human adult stem cells.
They say it is the first time a complex, anatomically-sized bone has been accurately created in this way.
It is hoped the technique could be used not only to treat disorders of the specific joint, but more widely to correct problems with other bones too.
The Columbia University study appears in Proceedings of the National Academy of Sciences.
The bone which has been created in the lab is known as the temporomandibular joint (TMJ).
Problems with the joint can be the result of birth defects, arthritis or injury.
Although they are widespread, treatment can be difficult.
The joint has a complex structure which makes it difficult to repair by using grafts from bones elsewhere in the body.
The latest study used human stem cells taken from bone marrow.
These were seeded into a tissue scaffold, formed into the precise shape of the human jaw bone by using digital images from a patient.
The cells were then cultured using a specially-designed bioreactor which was able to infuse the growing tissue with exactly the level of nutrients found during natural bone development.
Big potential
Lead researcher Dr Gordana Vunjak-Novakovic said: “The availability of personalised bone grafts engineered from the patient’s own stem cells would revolutionise the way we currently treat these defects.”
Dr Vunjak-Novakovic said the new technique could also be applied to other bones in the head and neck, including skull bones and cheek bones, which are similarly difficult to graft.
The option to engineer anatomically pieces of human bone in this way could potentially transform the ability to carry out reconstruction work, for instance following serious injury or cancer treatment.
She said: “We thought the jawbone would be the most rigorous test of our technique; if you can make this, you can make any shape.”
She stressed that the joint created in the lab was bone only, and did not include other tissue, such as cartilage. However, the Columbia team is working on a new method for engineering hybrid grafts including bone and cartilage.
Another major challenge for scientists will be to find a way to engineer bone with a blood supply that can be easily connected to the blood supply of the host.
Professor Anthony Hollander, a tissue engineering expert from the University of Bristol who helped produce an artificial windpipe last year, said there was still a lot of work to be done before the new bone could be used on patients.
But he said: “One of the major problems facing scientists in this field is how to engineer a piece of bone with the right dimensions – that is critical for some of these bone defects.
“This is a lovely piece of tissue engineering which has produced bone with a high degree of accuracy in terms of shape.”