The future of spine surgery: healing backs without screws or metal implants

Sept. 29, 2025
Contact: Janese Heavin, [email protected]
Photos by: Ben Stewart

Metal rods, screws and bone grafts have long been the backbone of spinal fusion surgeries - a fix for fractured spines, worn-out discs or bones that refuse to heal on their own.

The hardware works. But it's also rigid and invasive, and often leaves patients with lingering pain, stiffness and the need for follow-up surgeries down the road.

At the University of Missouri, a team of engineers is working on a new approach. In the Biomodulatory Materials Engineering Laboratory in the Roy Blunt NextGen Precision Health building, researchers led by Principal Investigator Bret Ulery are building a future where spines heal not through steel, but through biology - using tiny, bioactive materials made from therapeutic peptides to guide the body's natural repair processes from the inside out.

"What we're doing is trying to understand and leverage how the body can be guided to regenerate its own bone tissue," Ulery, an associate professor in the College of Engineering, said. "We want to convince the body to better heal itself."

With almost $2 million in new funding over the next five years from the National Institutes of Health, Ulery's team is developing soft, smart alternatives to metal implants using both synthetic polymers made from chemicals and biological polymers made largely from plant carbohydrates. These materials can be tailored to stimulate bone growth, reduce inflammation and dissolve harmlessly once healing is complete.

One of their most promising drug delivery tools is micelles - biodegradable particles formed by peptide amphiphiles. These structures act like smart delivery vehicles: they can carry drugs, release bioactive signals or even prompt stem cells to start regenerating tissue. In parallel, the team is building computational models to predict how different peptide sequences will behave, speeding up the design of these micelles and other healing systems.

The science is promising, and for Shwetha Ramachandra, a graduate student on the team, it's also deeply personal.

Five years ago, Ramachandra fell and fractured her L5 vertebra. She initially tried physical therapy and injections to manage the pain but to no avail. Eventually - and reluctantly - she underwent spinal fusion surgery.

"Metal plates and screws are not compatible with natural bone," she said. "And I don't know how this is going to affect me in the future. I have a greater chance of getting additional fractures, experiencing pain and having to have more surgeries."

Spinal fusion is most often performed on older adults, whose spines wear down with age. In the U.S., doctors perform more than 30,000 spinal fusions a year.

The same type of biomodulatory materials - engineered to guide the body's healing responses - being developed for spinal repair could also revolutionize treatments for infectious diseases, cancer and autoimmune conditions. Ulery and his team are adapting their peptide-based systems to create next-generation vaccines, tumor-targeting particles and materials to promote craniofacial repair such as healing jawbone fractures.

"I'm really hopeful that in the next 10 to 15 years, we'll have a material that can help a lot of people," Ramachandra said. "This isn't just a graduate research project. It's so much more than that."

MU College of Engineering

NextGen