The debilitating, chronic loss of joint cartilage known as osteoarthritis causes pain and bone decay for hundreds of millions of people every day, but new help may be on the way – in the form of a simple, single shot.
Based on ongoing animal experiments, injecting a carefully engineered, slow-release drug-delivery system into the damaged joint can coax the body’s own cartilage and bone cells to carry out an effective repair job in just a few weeks.
“In two years, we were able to go from a moonshot idea to developing these therapies to demonstrating that they reverse osteoarthritis in animals,” says chemical and biological engineer Stephanie Bryant, from the University of Colorado (UC) Boulder.
Having completed the first tranche of the animal experiments, the team is ready to move on to phase two. This will gather further data on safety and toxicology, laying the groundwork for human clinical trials.
“Our goal,” says Bryant, “is not just to treat pain and halt progression, but to end this disease.”
Right now, there is no cure for osteoarthritis: Either the pain has to be managed, or the joint has to be replaced with a metal or plastic substitute.
The research underway here (and not yet peer reviewed) potentially points to a solution that rallies the body’s own cells to repair damaged joints.
Besides their drug delivery system, the team are developing a injectable ‘implant’ that sets in place and recruits the body’s cells to patch up gaps in cartilage. Ultimately, the aim is to have different options for different stages of the condition.
There are actually four stages of osteoarthritis, from early and mild cartilage loss to a complete lack of cartilage and intense pain as bone meets bone – this is where the stiffness, swelling, and inflammation will be at its worst.
“At the moment, the options for many patients are either a massive, expensive surgery or nothing,” says Evalina Burger, a professor and chair of the Department of Orthopedics at UC Anschutz.
“There’s not a lot in between.”
Considering how common osteoarthritis is, how painful it can be, and how much it limits mobility and day-to-day life, there are now numerous research efforts underway looking at treatment options.
The amount of cartilage in our joints naturally decreases over time, but regular exercise is one way you can protect against this. Stronger muscles reduce the strain on joints, and movement pushes nutrient-rich fluids through them.
Earlier this year, Stanford University researchers were able to identify a specific protein responsible for the loss of cartilage that comes with aging – and reducing levels of that protein may help protect joints into old age.
Meanwhile, semaglutide – the active ingredient in drugs such as Ozempic and Wegovy – has also shown promise as an osteoarthritis treatment, through the way that it boosts cell metabolism and encourages healthy cartilage to remain in place.
It’s still going to take some time for actual treatments to be developed, but these research efforts are encouraging.
The team behind the injection treatment is hopeful that clinical trials can get underway within the next 18 months – but that depends on their next round on animal experiments.
Related: Ozempic-Like Drugs May Increase Risk of Bone And Joint Conditions
The research is being funded by the Novel Innovations for Tissue Regeneration in Osteoarthritis (NITRO) program, an initiative from the Advanced Research Projects Agency for Health (ARPA-H) that’s run by the US Department of Health and Human Services.
“Through ARPA-H, we are driving toward a future where people don’t have to wake up in pain, give up activities they love, or face major surgeries and repeat joint replacements – so they can stay active, independent, and healthy for longer,” says Alicia Jackson, Director of the ARPA-H.

