Researchers pioneer 3D-printed stem cell scaffolds to aid spinal cord injury recovery

Rats with completely severed spinal cords regained function after receiving 3D-printed stem cell scaffolds in a breakthrough that could pave the way for new treatments.

The approach combines 3D printing, stem cell biology and lab-grown tissues to develop a potential therapy for spinal cord injuries – damage to the bundle of nerves running through the spine that can cause paralysis.

Scientists at the University of Minnesota Twin Cities created a 3D-printed structure known as an organoid scaffold, made up of microscopic channels filled with regionally specific spinal neural progenitor cells (sNPCs) – cells derived from human adult stem cells that can turn into specific nerve cell types.

That there are an estimated 4,400 new cases of spinal cord injury per year in the UK, with no way to completely reverse the damage.

A major hurdle is that nerve cells die and fail to regrow across the injured site.

The new scaffold helps tackle this by directing stem cell growth through the printed channels.

Guebum Han is a former University of Minnesota postdoctoral researcher in mechanical engineering and first author of the study, who now works at Intel.

Han said: “We use the 3D-printed channels of the scaffold to direct the growth of the stem cells, which ensures the new nerve fibres grow in the desired way.

“This method creates a relay system that when placed in the spinal cord bypasses the damaged area.”

When transplanted into rats with completely severed spinal cords, the cells developed into neurons and extended fibres in both directions – rostral (toward the head) and caudal (toward the tail) – forming connections with the animals’ existing nerve circuits.

Over time, the new nerve cells integrated seamlessly into the spinal cord tissue, leading to significant functional recovery in the animals.

Ann Parr, professor of neurosurgery at the University of Minnesota, said: “Regenerative medicine has brought about a new era in spinal cord injury research.

“Our laboratory is excited to explore the future potential of our ‘mini spinal cords’ for clinical translation.”