A squishy cartilage-like material has been developed by researchers at the University of Cambridge. It can be loaded up with either long-term or short-term pain killers that are released when the material senses chemical stress from arthritis.
One of the major issues with our joints as we age is that once the cartilage that cushions them degrades, it never grows back because it lacks a blood and nerve supply. This leads to pain, sometimes caused by bone-on-bone contact, and can eventually cause osteoarthritis which can lead to permanent joint dysfunction.
Means to repair or regrow cartilage artificially, however, could slow or even halt this process, and there are already some products on the market that function in this capacity.
Seeking to take artificial cartilage to the next level, the Cambridge researchers developed a material known as a hydrogel – a water-rich gel-like substance that is the most commonly studied material as a cartilage replacement. Their hydrogel has a twist, however. It can respond to changing pH levels in the body.
When arthritis pain flares up, the area around the offending joint becomes inflamed and slightly acidic. So the Cambridge material is designed to become a little softer and jelly-like in this lower pH environment. When the material is loaded up with pain killers and/or anti-inflammatory drugs, they would be released as the hydrogel softens, interrupting the pain pathway and bringing relief to patients.
“These materials can ‘sense’ when something is wrong in the body and respond by delivering treatment right where it’s needed,” said first study author Stephen O’Neill. “This could reduce the need for repeated doses of drugs, while improving patient quality of life.”
To test out their material, the researchers loaded it up with a fluorescent dye as a stand-in for a pain-relieving drug. Sure enough, at a pH level representing normal body chemistry, the hydrogel stayed stable. When the pH level was lowered to create an acidic environment, the dye was released.
The researchers say that while the material now needs extensive testing in in vitro models – which they plan to do – it holds the potential to dramatically improve not only arthritis symptoms but other conditions in the body that could benefit from targeted drug delivery.
“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,” said O’Neill.
The study detailing the hydrogel has been published in the Journal of the American Chemical Society.
Source: University of Cambridge
