‘Living’ cartilage grown using stem cells could prevent hip replacement surgery
An alternative to hip replacement surgery may be in sight. In the Proceedings of the National Academy of Sciences, researchers reveal how it may be possible to use a patient’s own stem cells to grow new cartilage in the shape of a hip joint.
The researchers, led by Bo Chen, an associate professor of ophthalmology at Yale University School of Medicine in New Haven, CT, report their work in the journal Cell Reports.
According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), osteoarthritis is the primary cause of hip joint damage that requires hip replacement surgery, causing severe pain and disability.
Hip replacement surgery, also known as arthroplasty, involves surgically removing the diseased part of the hip and replacing it with new, prosthetic parts. Each year in the United States, more than 332,000 hip replacement surgeries are performed.
In their study, the researchers describe how new cartilage can be grown from a patient’s own stem cells, which are extracted from fat under the skin. The new cartilage is grown to cover a 3-D, synthetic scaffold that can be molded into the exact shape of a patient’s hip joint.
This cartilage-covered scaffold can be implanted onto the surface of the patient’s damaged hip joint. The team explains that this could alleviate pain caused by arthritis and, for some patients, it could delay or halt hip replacement surgery.
The scaffold was created using around 600 biodegradable bundles of fiber that are woven together, producing a hardy fabric that has the ability to work like normal cartilage.
“As evidence of this, the woven implants are strong enough to withstand loads up to 10 times a patient’s body weight, which is typically what our joints must bear when we exercise,” says study co-author Franklin Moutos, Ph.D., vice president of technology development at Cytex Therapeutics Inc.
What is more, the researchers explain how, by inserting a gene into the newly grown cartilage, they can trigger the release of anti-inflammatory molecules that have the potential to stop arthritis from returning.
“When there is inflammation, we can give a patient a simple drug, which activates the gene we’ve implanted, to lower inflammation in the joint,” explains Guilak. “We can stop giving the drug at any time, which turns off the gene.”
He adds that this gene therapy component is key; increased levels of inflammatory molecules in a joint can increase pain and damage cartilage. Having the ability to reduce levels of these molecules can protect the newly grown cartilage and promote long-term functioning.
The researchers believe their novel implant may one day provide a much-needed alternative to hip replacement surgery for the millions of patients with osteoarthritis – many of whom are younger patients aged 45-65.
The team says the implants are now being tested in animal models, and if they are successful, they could reach human testing within the next 3-5 years.