The cells may repair cartilage (Copyright: Cardiff University)
Stem cells offer a potential way to repair cartilage damaged by osteoarthritis, say scientists.
They have identified a type of stem cell which can be transformed into cartilage cells known as chondrocytes.
In theory, it should be possible to create new chondrocytes in sufficient numbers to achieve a real therapeutic effect for osteoarthritis patients.
The Cardiff University work was presented to the UK National Stem Cell Network Annual Science Meeting.
Osteoarthritis, which affects more than two million people in the UK, occurs when changes in the make-up of the body's cartilage causes joints to fail to work properly.
At its worse it can bring about the break-up of cartilage, causing the ends of the bones in the joint to rub against each other.
This results in severe pain and deformation of the joint.
One current treatment for younger patients is to harvest cartilage cells from neighbouring healthy cartilage and transplant them into the damaged area. Unfortunately, only a limited number of cells can be generated.
Immature stem cells have the ability to become any tissue in the body.
However, the cell identified by the Cardiff team is at a more advanced stage, where it has lost some of its plasticity but not its ability to become a chondrocyte if cultured in the lab in the right way.
Lead researcher Professor Charlie Archer said: "We have identified a cell which, when grown in the lab, can produce enough of a person's own cartilage that it could be effectively transplanted.
"There are limitations in trying to transplant a patient's existing cartilage cells but, by culturing it from a resident stem cell, we believe we can overcome this limitation.
"This research could have real benefits for arthritis sufferers and especially younger active patients with cartilage lesions that can progress to whole scale osteoarthritis."
The Cardiff team have now started animal tests, and hope to launch a clinical trial next year.
Professor Alan Silman, medical director of the Arthritis Research Campaign, which part-funded the study, said: "How to stop or even reverse the wearing away of cartilage that is the hallmark of osteoarthritis has been a treatment goal which up to now has not proved possible.
"If we can translate these successes from the laboratory into treating patients the possibility opens up of making a remarkable impact on this common painful and disabling condition."