Scientists have restored movement in rats with severed spinal cords using a 3D-printed scaffold containing stem cells.
The research suggests new possibilities for tackling paralysis caused by spinal cord injuries, which currently have no cure.
These injuries occur when neurons – nerve cells that transmit messages through the body – die and cannot regrow across the damaged area.
Researchers built a scaffold with tiny printed channels, then filled it with spinal neural progenitor cells (sNPCs). These are cells able to multiply and develop into other types.
The scaffolds were transplanted into rats with fully severed spinal cords.
Guebum Han is first author of the study and a mechanical engineer at Intel Corporation.
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.”
The transplanted sNPCs developed into neurons and extended fibres up and down the spinal cord, linking with the animals’ own neurons.
Over time, the new cells integrated into the cord tissue, forming a functional bridge across the injury site.
The researchers noted that spinal cord injury affects an estimated 255,000 to 383,000 people in the US, with no effective treatments currently available.
They described the scaffold as creating “mini spinal cords” that bypass damaged areas and restore neural communication.
Ann Parr is a co-author and neurosurgeon at the University of Minnesota.
Parr 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.”
