3D-Printed Structures for Mending Spinal Cord Injuries

In the realm of medical science, researchers are making significant strides in the field of spinal cord injury (SCI) treatment. One of the promising avenues of research is the development of specialized stem cells, known as sNPCs, which are programmed to be specific to the human spinal cord. The goal is to use these cells for future cell-replacement therapies following SCI.

A notable study, published in the peer-reviewed scientific journal Advanced Healthcare Materials, saw researchers from the Wyss Institute for Biologically Inspired Engineering at Harvard University create an ultra-thin implant that delivers electric currents to the injured part of the spinal cord. This implant mimics natural signals to stimulate nerve healing, offering a potential solution for SCI patients.

Meanwhile, scientists at the University of Minnesota Twin Cities have built a 3D-printed scaffold with microscale channels that guides stem cells' growth into working nerve cells. These scaffolds, made of silicone, a synthetic polymer known for its high biocompatibility, excellent oxidation resistance, and high gas permeability, could pave the way for more effective SCI treatments.

Researchers at the same university have also created 3D-printed spinal cord organoid scaffolds using human induced pluripotent stem cell (iPSC)-derived sNPCs. In a study, they demonstrated that when transplanted into rats whose spinal cords were entirely severed, the cells successfully differentiated into neurons, leading to considerable functional recovery.

The global burden of SCI is significant. In the US alone, over 300,000 people are suffering from SCI, and more than 15 million people worldwide are living with the condition. Any damage to the spinal cord can affect our movement, function, and sensation, making effective treatments essential.

Activities like falls, driving incidents, and motorcycle and automobile crashes can cause damage to the spinal cord. The spinal cord, a central nerve structure extending from the brain down to the lower back, is protected by the vertebrae and three layers of membranes. It is organized into the cervical spine (neck), thoracic spine (upper back to below navel), lumbar spine (lower back), and sacral spine (butt to tailbone), with a total of 31 segments, consisting of 8 cervical, 12 thoracic, five lumbar, five sacral, and one coccygeal segment.

Interestingly, males are more commonly affected by SCI than females. Last year, a team of surgeons, neuroscientists, and engineers from the University of Cambridge developed 'wraparound' implants to treat SCI, while this year, researchers demonstrated impressive rates of recovery for SCI by combining closed-loop vagus nerve stimulation (CLV) with individualized rehabilitation.

The research teams aim to scale up the production of their technologies and continue developing their combination of technologies: sNPCs, organoid assembly, and 3D printing strategies for future clinical applications. Effective treatments are crucial to alleviate the global burden of SCI and offer hope for those affected by this debilitating condition.