Researchers at Duke University have created a revolutionary gel-based material designed to replace knee cartilage. This new substitute is stronger and more durable than natural cartilage, offering hope for those suffering from osteoarthritis. Nearly one in six adults worldwide are affected by this condition, which is characterized by knee pain due to worn-out cartilage. This gel-based substitute could provide an alternative to knee replacement surgery, presenting a more effective treatment option for patients with knee pain. Sparta Biomedical is developing and testing the implant in sheep, and human clinical trials began in 2023.

In testing, the hydrogel was found to be 26% stronger than natural cartilage in tension and 66% stronger in compression. The Duke University team addressed several design challenges in creating the implant, such as securely attaching it to the joint, which previous studies had not successfully achieved.

The attachment method involves cementing and clamping the hydrogel to a titanium base, which is then pressed and anchored into a hole where the damaged cartilage used to be. The hydrogel mimics the smooth, slippery, and cushiony nature of real cartilage, providing a more durable and effective treatment option for knee pain sufferers.

Knee pain is a common issue, particularly among older adults, and can result from injury, overuse, or conditions like osteoarthritis. Osteoarthritis affects nearly 867 million people globally, causing chronic pain, inflammation, and stiffness by wearing down the cartilage that cushions the ends of bones.

Traditional treatments for knee pain include over-the-counter pain relievers, physical therapy, and steroid injections. However, for some patients, these treatments are insufficient, leading to the need for knee replacement surgery. This surgery involves removing damaged cartilage and replacing it with an artificial joint made of metal or polyethylene, which requires months of rehabilitation and carries risks such as infection and blood clots.

The new gel-based cartilage substitute developed at Duke University offers a less invasive and potentially more effective treatment. Led by chemistry professor Benjamin Wiley and mechanical engineering and materials science professor Ken Gall, the team published their findings in the journal Advanced Functional Materials.

The hydrogel is made from thin sheets of cellulose fibers infused with a polymer called polyvinyl alcohol. The cellulose fibers act like collagen fibers in natural cartilage, providing strength when stretched, while the polyvinyl alcohol helps the gel return to its original shape. The resulting material is a Jello-like substance that is 60% water but surprisingly strong. It can withstand more force than natural cartilage and is three times more resistant to wear and tear.

The researchers tested the implant’s durability by spinning artificial and natural cartilage against each other a million times, simulating the pressure experienced by the knee during walking. Using high-resolution X-ray scanning techniques, the scientists found that the surface of the implanted cartilage remained smooth and intact after the million rotations, indicating minimal wear and tear.

The researchers were thrilled with these results, which suggest that the implant could potentially last for many years without needing replacement. However, further testing is necessary to confirm their findings and ensure the implant’s safety and effectiveness for human use.

To this end, the team began planning animal studies to evaluate the implant’s long-term safety and effectiveness. They also explored potential partnerships with medical device companies to bring their technology to market and make it available to patients in need.

As news of the breakthrough spread, the research team received numerous accolades and awards for their work. They were invited to present their findings at international conferences and symposia, where they shared their insights with other researchers and medical professionals.

By Impact Lab