Prof. Tal Dvir. Photo: Sagol Center for Regenerative Biotechnology

Israeli scientists from Tel Aviv University say they have engineered 3D human spinal cord implants to treat paralysis, which if successful in clinical trials in human patients could help people stand up and walk again.

The study, conducted in mice and led by Prof. Tal Dvir of the Sagol Center for Regenerative Biotechnology, showed an 80 percent success rate in restoring walking ability. The results were published in the peer-reviewed journal Advanced Science.

“The model animals underwent a rapid rehabilitation process, at the end of which they could walk quite well,” Dvir said Monday. “This is the first instance in the world in which implanted engineered human tissues have generated recovery in an animal model for long-term chronic paralysis — which is the most relevant model for paralysis treatments in humans.”

“Individuals injured at a very young age are destined to sit in a wheelchair for the rest of their lives, bearing all the social, financial, and health-related costs of paralysis,” he said. “Our goal is to produce personalized spinal cord implants for every paralyzed person, enabling regeneration of the damaged tissue with no risk of rejection.”

Dvir noted that millions of people around the world are paralyzed due to spinal injury caused by traffic accidents, falls and sports-related accidents — with no effective treatment for their condition.

The organ engineering technology he developed with his research team relies on taking a small biopsy of fatty tissue from the abdomen of a patient, and reprogramming the fat cells into embryonic-like stem cells.

“This tissue, like all tissues in our body, consists of cells together with an extracellular matrix (comprising substances like collagens and sugars),” Dvir explained. “After separating the cells from the extracellular matrix we used genetic engineering to reprogram the cells, reverting them to a state that resembles embryonic stem cells — namely cells capable of becoming any type of cell in the body.”

From the extracellular matrix, the researchers produced a personalized hydrogel.

“We then encapsulated the stem cells in the hydrogel and in a process that mimics the embryonic development of the spinal cord we turned the cells into 3D implants of neuronal networks containing motor neurons,” Dvir continued.

In the next stage, the human spinal cord implants were implanted according to two trial groups: those who had only recently been paralyzed and those who had been paralyzed for a long time. Following the implantation, 100 percent of the group with acute paralysis and 80 percent of those with chronic paralysis regained their ability to walk, the researchers said.

Following the study, the researchers are preparing for clinical trials in human patients.

“Our goal for the next few years is to engineer personalized spinal cord implants to repair tissue damaged from injury without the risk of implant rejection,” they stated. “The ability of the implants to replace the resected scar tissue and rewire the injured spinal cord of humans may represent a novel personalized cell therapy approach.”

A preclinical program has already been discussed with the US Food and Drug Administration (FDA), according to Dvir. “We hope to reach the stage of clinical trials in humans within the next few years,” he said, “and ultimately get these patients back on their feet.”