Scientists are predicting a "cure" for arthritis within the next decade after they successfully grew human cartilage from a patients’ own stem cells for the first time.
The breakthrough paves the way for cartilage transplant operations for more than two million people who suffer the most severe form of the bone disease, osteoarthritis, which leaves them unable to walk and in constant pain.
Experts from the University of Bristol took just over a month to grow a half-inch piece of cartilage using stem cells, which are self-renewing and have the ability to grow into blood, bones or organs.
The cells were taken from the bone marrow of pensioners undergoing National Health Service replacement surgery due to the disease.
Crucially, the new technique is expected to overcome problems of transplant rejection because the patient’s own cells would be used to create the cartilage. This would also avoid the ethical concerns over the use of human embryos in stem cell research. The most potent stem cells are found in human embryos, but a lesser supply can also be found in adult bone marrow.
Tests have shown that the laboratory-grown cartilage is of better quality than any previous attempts at tissue engineering. This means it should be "springy" enough to work in a knee joint.
Transplant trials on NHS osteoarthritis patients are expected within two years, following the development by Prof Anthony Hollander and his team at Southmead Hospital in Bristol.
Prof Hollander, the Arthritis Research Campaign professor of rheumatology and tissue engineering, has devised a way of making adult bone marrow stem cells grow into cartilage within 40 days in the laboratory.
The profrssor, who last night described the experiment as a "breakthrough", now expects to grow several lumps of cartilage from the same patient, enough to make a transplant possible.
Prof Hollander said: "Our aim within a decade is to develop a cure for arthritis, and we have taken an important step down that road. This is the first time that proper cartilage has been grown in a test tube.
"There have been other attempts but tests showed that the cartilage grown was not great quality, as there has been a tendency for cells to calcify and for it to become too fibrous.
"We are very excited because this cartilage does not appear to have those problems. The next step will be to grow several lumps and try to piece together enough to provide a workable transplant for an area devastated by osteoarthritis."
In osteoarthritis, cartilage – which acts as a shock absorber wherever bone meets bone – becomes damaged, erodes away and the underlying bone becomes thicker.
Almost eight million people in Britain suffer osteoarthritic joints, and two million cases are severe enough to require specialist care, with painkillers their main treatment.
Population changes suggest that these numbers will double over the next 20 years, presenting a huge challenge to the NHS as it tries to meet the booming demand for hip and knee replacements.
To grow cartilage, scientists took stem cells from bone marrow and placed them in a nutrient-rich solution, containing growth factors to help to boost cell development.
The cells were grown up a tiny scaffold made of polyglycolic acid, which is the same material used to make dissolvable, surgical stitches. This means that once the cartilage is transplanted, the scaffold should melt away. Full details are due to be published in a scientific journal early next year.
Jane Tadman, a spokesman for the Arthritis Research Campaign, said: "We are very excited by Prof Hollander’s work. He is taking tissue engineering a step further in the hope that it will bring relief for the two million people badly affected by osteoarthritis.
"This offers some hope where there has been none."
