3D printed implant repairs spinal cords
23 Jan 2019 by Evoluted New Media
A 3D-printed implant loaded with neural stem cells has been used to repair severe spinal cord injuries in rats.
Researchers at the University of California printed 2mm-sized implants in 1.6 seconds. These implants contain 200-micrometer-wide channels that guide neural stem cell and axon growth along the spinal cord injury.
Co-author of the study Kobi Koffler said: “The scaffolding provides a stable, physical structure that supports consistent engraftment and survival of neural stem cells. It seems to shield grafted stem cells from the often toxic, inflammatory environment of a spinal cord injury and helps guide axons through the lesion site completely.”
The process is scalable to human spinal cord sizes; 4cm-sized implants modelled from MRI scans of human spinal cord injuries were printed in 10 minutes.
“The new work puts us even closer to the real thing, because the 3D scaffolding recapitulates the slender, bundled arrays of axons in the spinal cord,” Koffler said. “It helps organise regenerating axons to replicate the anatomy of the pre-injured spinal cord.”
The 2mm implant has hollow portals through which implanted neural stem cells can extend axons into host tissues. Months after the scaffold-type implant was inserted, new spinal cord tissue had connected the severed ends of the host spinal cord. As a result, treated rats had motor improvement in their hind legs.
Co-senior author Shaochen Chen said: “Like a bridge, it aligns regenerating axons from one end of the spinal cord injury to the other. Axons by themselves can diffuse and regrow in any direction, but the scaffold keeps axons in order, guiding them to grow in the right direction to complete the spinal cord connection.”
The research was undertaken by scientists at the University of California San Diego School of Medicine and Institute of Engineering in Medicine. Results were published in Nature Medicine.
