An interesting science report was doing the rounds last month.
“Rubbery ‘goo’ could spell the end for knee replacement surgery,” was how the Daily Telegraph’s headline writers described it.
If the word “goo” wasn’t eye-catching enough, the research findings certainly were. The new material – developed in the US and initially trialled in sheep – appears to be capable of regenerating cartilage that has been lost to osteoarthritis.
So how promising is the new research? Let’s look at the story in more detail.
Who is behind the discovery?
The study comes from a team at Northwestern University in Chicago. It was led by Dr Samuel Stupp, an award-winning scientist who specialises in developing advanced biomaterials for use in regenerative medicine. The substance they created was injected into the hind legs of sheep – specifically the stifle joint, which has many similarities to the human knee.
Why is it significant for arthritis?
Osteoarthritis is a wear-and-tear condition. It’s what happens when we lose the smooth cartilage that protects bone endings, either through long-term attrition or injury. The big problem with articular cartilage is that, unlike many other materials in our bodies, it can’t replenish itself once lost. So treatment often focuses on managing symptoms, relieving pain and, sometimes, replacement surgery.
What’s in the new substance?
Although it looks like a rubbery goo, the scientists explain, “the material is actually a complex network of molecular components, which work together to mimic cartilage’s natural environment in the body.” It contains two key ingredients: hyaluronic acid, a natural substance often used in skincare products, and a “bioactive peptide”, which binds to a protein (“transforming growth factor beta-1”, or TGFb-1) that’s essential to cartilage growth.
How does it work?
The material has two main goals. One is to create a “scaffold” that supports the regeneration of any new cartilage tissue. The second is to send signals encouraging the cells to repair. The sheep trial results, says the team, were quite dramatic: “Within just six months, [we] observed evidence of enhanced repair, including the growth of new cartilage containing the natural biopolymers (collagen II and proteoglycans), which enable pain-free mechanical resilience in joints.”
Could the “goo” be a game-changer?
It’s important to treat any new trial with a healthy dose of caution. Perhaps especially when it comes to arthritis repair. As the scientists themselves point out, cartilage is “incredibly difficult to regenerate”. Though there have been plenty of attempts at it over the years, few have met with great success. It’s also worth remembering that surface damage isn’t the only issue at stake in osteoarthritis. The damage might be due to a mechanical issue like malalignment, for instance, where grinding pressure is focused on one portion of the knee. In that situation, any new substance we put into the joint is likely to wear away again like the original cartilage. So, the “environment” of the knee is crucial.
With all that said, however, there are reasons to be optimistic about this new research. Biomechanical engineering is a growth area in modern medicine, and the initial trial results suggest that – if replicated in humans, which is probably still a long way off yet – the future of cartilage self-repair could be exciting. “Not only did new cartilage grow to fill the defect as the scaffold degraded, but the repaired tissue was consistently higher quality compared to the control,” says the Northwestern team. A breakthrough moment? It’s too early to say at this point. But the direction of travel is very encouraging.
You can read more about the study in this article from Northwestern University: New biomaterial regrows damaged cartilage in joints
Interested in exploring more on this topic? You may find these articles helpful
What happens if you damage your knee cartilage?
