Printing a Path to
Spinal Repair
Treating central nerve damage has remained one of medicine’s toughest challenges. A newly developed 3D-printed implant combines bioactive polymers and electroconductive materials to potentially guide nerve regeneration.
Written by Kayt Sukel
More than 15 million people are living with spinal cord injuries across the globe, according to the World Health Organization. These injuries, often resulting from trauma, can result in paralysis, loss of sensory function, chronic pain, and a host of other medical issues.
To date, this kind of central nerve damage has been nearly impossible to treat. But there are promising studies demonstrating that electrical stimulation may encourage neurons to grow and reconnect, restoring some function—but only if clinicians can find a way to effectively deliver it to the right place.
Now, researchers from the RCSI University of Medicine and Health Sciences in Dublin have developed a 3D-printed implant that may overcome this challenge.
“Spinal cord injury is very complex—and one challenge in treating it is that everyone’s injury is completely different,” said Fergal O’Brien, deputy vice chancellor for research and innovation and professor of bioengineering and regenerative medicine at RCSI, where he also heads the Tissue Engineering Research Group (TERG). “A complex injury requires a complex solution. We’ve been targeting a way to help regrow the nerve cells in the periphery using a biomaterial scaffold, loading them with stem cells and gene therapies.”
With those new studies suggesting electrical stimulation may also provide an assist, O’Brien’s team looked to 2D materials, typically used for batteries and energy storage, to combine with their existing biologically active materials to see what might happen. The team included biomedical engineers, materials scientists, and biologists. Together, they came up with a design that combines ultra-thin, electroconductive nanomaterials with softer bioactive polymers to create a flexible implant that could help channel electrical stimulation to where it’s most needed.
“Because this implant is 3D printable, if you had a certain size lesion on the spine, you could potentially print the implant to match the size of the lesion. A surgeon could then place it on the injury.”
—Fergal J. O'Brien, deputy vice chancellor for research and innovation and professor of bioengineering and regenerative medicine at RCSI
“We’ve been putting a lot of focus on combining these electrically conductive materials with the natural polymers we’ve used for peripheral nerve damage,” O’Brien explained. “We used 3D printing to create these constructs with polymers, holding them with the electroactive materials, so we could begin looking at how to better develop nerve functionality.”
O’Brien said that many implant ideas have been stymied by concerns about cytotoxicity, which may do more harm to the damaged cells than good. To address this, his team’s design uses as little of the electroactive material as possible. He added that their design also needed to be able to guide neurons through channels, so as nerves began to grow, they wouldn’t be cut off by potential scarring.
As a result, their implant boasts a fine mesh of tiny fibers that can conduct electricity to cells, as well as molecules that help promote healing and suppress inflammation. When tested in a laboratory setting, they found this unique and flexible 3D-printed implant could effectively deliver the necessary signals to neurons and stem cells—and could encourage them to grow.
“This ended up being a very complex 3D printing process. We use melt electrowriting (MEW), which combines 3D printing with electrospinning,” he said. “By using this cool technique, we can produce 3D structures with very, very thin fibers made from polycaprolactone, a bioactive polymer that is already used clinically in different implants, and then coat that with the electroactive 2D materials.”
With the addition of proteins and molecules like hyaluronic acid and collagen type 4, the implant not only provides stimulation, but molecules that promote a more neurotrophic environment. When put together in this innovative implant, they can encourage nerve cells to grow and regain function.
“Because this implant is 3D printable, if you had a certain size lesion on the spine, you could potentially print the implant to match the size of the lesion,” he said. “A surgeon could then place it on the injury.”
O’Brien said the team proposes to start preclinical testing with the Mayo Clinic in Rochester, Minn., come fall.
Immunohistochemical analysis of neuronal coverage, morphology, and axonal extension. Image: Woods, et al., July 15, 2025
He emphasized that their current success was built on the back of several different studies conducted over the last decade. Collaborations included organizations like Research Ireland, the AMBER Centre (Research Ireland’s hub for advanced materials and bioengineering research), and even the Irish Rugby Football Union Charitable Trust (IRFU-CT). The IRFU-CT, O’Brien explained, includes players who have suffered from spinal injuries and were a part of the research team from the beginning.
“From the outset, we worked with people living with spinal cord injury. And I don’t mean we would tell them what we were doing. They influenced our experimental design from the beginning and have really informed what we’ve done based on their lived experience,” he said. “As a university of health sciences, our patient is always our end user. While we want to produce Ph.D. students and publish good papers, it’s even more important that our science makes an impact and can translate clinically so we can help people.”
Kayt Sukel is a technology writer and author in Kansas City.
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