University of Wisconsin-Madison researchers have developed a promising technique for treating osteoarthritis using therapeutic blood clots activated by messenger RNA.
Osteoarthritis is the most common form of arthritis, affecting roughly 33 million adults in the United States, according to the Centers for Disease Control and Prevention. It occurs when cartilage in key joints like the knees and hips deteriorates, causing pain and stiffness and impeding mobility.
In a paper in the journal Bioactive Materials published online in December 2025, the UW-Madison research team led by William Murphy, a professor of biomedical engineering and orthopedics and rehabilitation, details its new approach. With further development, it could one day offer a more effective option than treatments such as steroid injections, hyaluronic acid injections or even joint replacement surgeries.
“The best-case scenario is that this could be an injectable or implantable treatment for patients who have advanced osteoarthritis,” says Murphy. “This would be an alternative to the existing methods for treatment, which generally don’t show a high level of long-term success.”
Following the lead of his lab’s previous work on mRNA-based vaccines, therapies for spinal cord injuries and more, the method relies upon mineral-coated microparticles to deliver mRNA that encodes for production of a protein that supports cartilage formation.
First, the team takes bone marrow aspirate (liquid bone marrow) and peripheral blood samples from a patient, mixes in the microparticles, and then forms the mixture into a blood clot. Then the mRNA-activated clot gets delivered to the site of the damage.
“This all happens in the same surgery,” says Murphy, whose lab specializes in therapies that leverage biologically inspired materials. “This is all intra-operative, and it uses materials derived from the patient.”
Whereas existing treatments such as arthroscopic chondroplasties can lead to the formation of fresh fibrocartilage tissue, that material doesn’t boast the same mechanical properties of joint cartilage. It also degrades more quickly. Unlike traditional tissue engineering approaches, however, the new method doesn’t require the use of a synthetic scaffold material upon which to grow cells.
After seeing success in rabbit models, the group will test its treatment strategy in a larger animal model before proceeding toward human clinical trials.
Murphy says his group is exploring the same approach to treat large skeletal muscle and bone defects as well.
William Murphy is the Harvey D. Spangler Professor of biomedical engineering and orthopedics and rehabilitation, as well as an H.I. Romnes Faculty Fellow and director of the Forward BIO Institute. Other UW-Madison authors on the paper include Brett Nemke, a research program manager in the School of Veterinary Medicine; Wan-Ju Li, an associate professor of biomedical engineering and orthopedics and rehabilitation; Mark Markel, a professor of medical sciences in the School of Veterinary Medicine; Yan Lu, a scientist in the School of Veterinary Medicine; Connie Chamberlain, a former scientist in the Murphy lab and current scientist in the Department of Surgery; Jae-Sung Lee, a former scientist in the Murphy lab and now an assistant professor at the University of Minnesota; Gianluca Fontana, a former scientist in the Murphy lab; MD-PhD student Joshua Choe; Hongli Jiao, an assistant scientist in Wan-Ju Li’s lab; and Michael Nelson and Margot Amitrano, graduate students in biomedical engineering.
Funding for the research came from a private gift from the Shannon family in support of the Musculoskeletal Regeneration Partnership, the National Institute on Aging (award number F30AG077748), and the UW-Madison Medical Scientist Training Program.
Top image of William Murphy by Joel Hallberg.