New smart artificial cartilage could revolutionize arthritis treatment

By Stephen Beech

Arthritis treatment could be revolutionized by a new "artificial cartilage" breakthrough.

Cambridge University scientists have developed a material that can sense tiny changes within the body - such as during an arthritis flare-up - and release drugs exactly where and when they are needed.

The "squishy" material can be loaded with anti-inflammatory drugs that are released in response to small changes in acidity (pH) levels in the body.

During an arthritis flare-up, a joint becomes inflamed and slightly more acidic than the surrounding tissue.

The material is designed to respond to that natural change in pH.

As acidity increases, the material becomes softer and more jelly-like, triggering the release of drug molecules that can be encapsulated within its structure.

Since the material is designed to respond only within a narrow pH range, the researchers say that drugs could be released "precisely" where and when needed - potentially reducing side effects.

If used as an artificial cartilage in arthritic joints, the Cambridge team say it could allow for the continuous treatment of arthritis, improving the efficacy of drugs to relieve pain and fight inflammation.

Arthritis affects more than 10 million people in the UK, costing the NHS an estimated £10.2 billion annually.

The condition is estimated to affect more than 600 million people worldwide.

While extensive clinical trials are needed before the material can be used in patients, the researchers say their approach could improve outcomes for people with arthritis, and for those with other conditions - including cancer.

The material, described in the Journal of the American Chemical Society, uses specially engineered and reversible crosslinks within a polymer network.

The sensitivity of those links to changes in acidity levels gives the material highly responsive mechanical properties, according to the research team led by Professor Oren Scherman.

More from this section

Space Travel Accelerates Cellular Aging, Researchers Say

Is aggressive behavior contagious?

New antibiotic beats deadly superbug in trials

He said, “For a while now, we’ve been interested in using these materials in joints, since their properties can mimic those of cartilage.

“But to combine that with highly targeted drug delivery is a really exciting prospect.”

First author Dr. Stephen O’Neill said: “These materials can ‘sense’ when something is wrong in the body and respond by delivering treatment right where it’s needed.

“This could reduce the need for repeated doses of drugs, while improving patient quality of life.”

Unlike many drug delivery systems that require external triggers such as heat or light, he explained that the new one is powered by the body’s own chemistry.

The researchers say that could pave the way for longer-lasting, targeted arthritis treatments that automatically respond to flare-ups, boosting effectiveness while reducing harmful side effects.

In lab tests, the research team loaded the material with a fluorescent dye to mimic how a real drug might behave.

They found that at acidity levels typical of an arthritic joint, the material released substantially more drugs compared with normal, healthy pH levels.

Co-author Dr. Jade McCune said: “By tuning the chemistry of these gels, we can make them highly sensitive to the subtle shifts in acidity that occur in inflamed tissue.

“That means drugs are released when and where they are needed most.”

The researchers say the approach could be tailored to several other medical conditions by fine-tuning the material's chemistry.

Dr. O’Neill added: “It’s a highly flexible approach, so we could in theory incorporate both fast-acting and slow-acting drugs, and have a single treatment that lasts for days, weeks or even months."

He said the next steps will involve testing the materials in living systems to evaluate their performance and safety.

If successful, Dr. O’Neill says the approach could open the door to a new generation of responsive biomaterials capable of treating chronic diseases with greater precision.