Researchers backed by the federal government have taken steps to transform osteoarthritis care, officials announced on April 6.

Columbia University scientists have created what they’re calling a living knee implant that provides a lifetime of stability to people who would otherwise undergo knee replacement surgery. The 3-D printed organ is made out of biodegradable “scaffolding” material infused with adult stem cells that regenerate the joint’s cartilage and bone tissues as the scaffolding disappears.

“We selected polymers that are new to the medical implant field,“ Nadeen Chahine, a professor of biomedical engineering at Columbia University Vagelos College of Physicians and Surgeons, said in a statement. ”The new materials allow us to balance strength, ductility, and manufacturability using 3D printing. We had to optimize the implant to achieve a design that wouldn’t fail mechanically, is safe for implantation in the body, and can seamlessly integrate into the clinical workflow.”

About 32 million Americans every year are affected by osteoarthritis, or the breakdown of cartilage—flexible tissue that helps joints move smoothly. Many undergo joint surgery to replace cartilage with titanium alloy implants.

Two other teams backed by funding from the the Advanced Research Projects Agency for Health (ARPA-H) have developed potential injectable treatments for patients who do not need joint replacement but who could use strengthened bone and/or cartilage.

Potential therapies from University of Colorado Boulder researchers successfully assisted in repairing damaged joints in animals in just weeks, while Duke University scientists have designed combination drugs that stimulate bone and cartilage regeneration.

The projects are part of a program launched in 2024 by ARPA-H, an agency created by Congress in 2022 that is part of the U.S. Department of Health and Human Services.

The program is called the Novel Innovations for Tissue Regeneration in Osteoarthritis (NITRO) and has the goal of eradicating osteoarthritis through regenerative therapies that can be injected and implanted.

“NITRO, ARPA-H’s first program, was launched with the question: What if we could make our joints heal themselves? Two years later, it’s not only possible, but quickly becoming a reality,” Ross Uhrich, manager of NITRO, said in a statement.

“NITRO is on track to transform osteoarthritis care for millions of Americans—we are moving from simply managing pain and swapping out worn joints to truly restoring natural movement, supporting longevity, and helping people live the lives they want,” added Alicia Jackson, ARPA-H’s director.

Officials said the three treatments have hit key milestones laid out in 2024 and are advancing to human clinical trials, the next step on the path to selling them to the public. Uhrich said the first trials will start in 18 months.

Trial requirements include having more than half of participants being women and having volunteers reflect populations most affected by osteoarthritis, including native Americans.