A University of Minnesota Twin Cities research team has combined 3D printing, stem cell biology, and lab-grown tissues to address spinal cord injury recovery.
The breakthrough method holds the potential to one day help people regain function after paralysis.
More than 300,000 Americans live with spinal cord injuries, according to the National Spinal Cord Injury Statistical Center.
Damage to the cord often leads to cell death and prevents nerve fibers from reconnecting. Current treatments cannot reverse this process, leaving paralysis permanent.
The Minnesota team set out to change that. They created a 3D-printed framework called an organoid scaffold. This scaffold contains microscopic channels filled with spinal neural progenitor cells, or sNPCs.
These cells, derived from human adult stem cells, can divide and transform into specific nerve cell types.
“We use the 3D printed channels of the scaffold to direct the growth of the stem cells, which ensures the new nerve fibers grow in the desired way,” said Guebum Han, former University of Minnesota postdoctoral researcher and first author of the paper.
Han, who now works at Intel Corporation, added, “This method creates a relay system that when placed in the spinal cord bypasses the damaged area.”
Testing the method in rats
The researchers implanted the scaffolds into rats with completely severed spinal cords. Over time, the sNPCs developed into neurons. The cells extended nerve fibers in both directions, toward the head and tail, to connect with the host spinal tissue.
The new neurons integrated smoothly with existing nerve circuits.
As the connections strengthened, the rats showed significant functional recovery. The findings demonstrated that the scaffold not only supported cell survival but also enabled reconnection across a severe injury.
“Regenerative medicine has brought about a new era in spinal cord injury research,” said Ann Parr, professor of neurosurgery at the University of Minnesota. She added that her team is eager to explore the clinical potential of what they call “mini spinal cords.”
Looking toward human use
Although the study remains in its early stages, the results suggest a new approach for future therapies. The researchers plan to scale up production and refine the technology for clinical trials.
The project brought together expertise across multiple disciplines. Alongside Han and Parr, contributors included Hyunjun Kim and Michael McAlpine from mechanical engineering, Nicolas S. Lavoie, Nandadevi Patil, and Olivia G. Korenfeld from neurosurgery, Manuel Esguerra from neuroscience, and Daeha Joung from physics at Virginia Commonwealth University.
Funding came from the National Institutes of Health, the State of Minnesota Spinal Cord Injury and Traumatic Brain Injury Research Grant Program, and the Spinal Cord Society.
The work represents a crucial step toward a long-term goal: restoring mobility and independence for people with spinal cord injuries.
While far from a cure, the study points to a new path that combines advanced manufacturing, stem cell science, and regenerative medicine.
The study is published in the journal Advanced Healthcare Materials.