Researchers at the University of Delaware have developed a “smart” hydrogel that can deliver medicine on demand – which potentially could be used to treat pain from osteoarthritis and other diseases.
Scientists believe polymer-based hydrogels, because of their toughness and plasticity, have several biomedical applications, including cartilage repair.
They can also be loaded with drugs and placed in the body, where the sponge-like gel biodegrades and slowly releases the drugs into the surrounding tissue.
The UD researcher team, which published its findings in the journal Biomacromolecules, believes that hyaluronic acid-based hydrogels can be injected into an injury site — such as a knee or hip — and that as a patient walks or undergoes physical therapy, the walking motion will cause accelerated release of drugs, reducing inflammation and pain.
Hyaluronic acid is a naturally occurring substance in cartilage, making it more readily accepted in the body.
“The idea of a smart hydrogel that can release medicine over time is not new,” said Xinqiao Jia, UD professor of materials science and engineering and biomedical engineering. “What’s new is our ability to have medicine released in response to force — a major challenge for people with osteoarthritis and other ‘wear and tear’ injuries that compromise a person’s ability to perform everyday activities.”
About a third of adults over the age of 65 suffer from osteoarthritis, a progressive disorder of the joints caused by inflammation of the soft tissue, which worsens over time and leads to thinning of cartilage. Osteoarthritis is the most common form of arthritis, affecting over 27 million Americans, according to the Arthritis Foundation.
In recent years, smart hydrogels have been created that respond to pH, temperature, DNA, light and other stimuli. Testing under laboratory conditions has confirmed that when hydrogel is compressed, the encapsulated drugs are discharged into the surrounding environment. Tests also confirmed the anti-inflammatory effect of the drugs.
University of Delaware researchers are now collaborating with colleagues at Rush University in Chicago to test the hydrogels in animal models.
Jia believes hydrogels could help treat a variety of conditions besides osteoarthritis, including ligament tears or other injuries.
“I have even considered whether we can leverage this hydrogel platform to reduce inflammation in patients with vocal fold disorders,” Jia said.
The research team is now investigating whether hydrogels can be infused with properties that could stimulate tissue regeneration and repair.
The work is funded through the National Science Foundation, National Institutes of Health and the state of Delaware. Biomacromolecules is a publication of the American Chemical Society (ACS).