Paralyzed Rats Can Walk Again After Israeli Scientists Inject Human Stem Cells
Israeli scientists from the prestigious Technion-Israel Institute of Technology and Tel Aviv University say they have successfully restored the walking ability and general mobility of paralyzed rats in a recent experiment using an engineered 3D construct embedded with human stem cells that also enabled the gradual rehabilitation of the damaged spine.
The researchers said many of the rats with spinal cord injury who were implanted with the constructs “regained fine motor control, coordination and walking pattern in sharp contrast to the untreated group that remained paralyzed.”
The construct consisted of a 3D tissue-engineered, biodegradable scaffold that provided an environment in which the cells, obtained from human gums, can “attach, grow and differentiate, maintain cell distribution, and provide graft protection following transplantation,” the scientists wrote.
The enhanced construct “formed a growth-permissive microenvironment that counteracted inhibitory signals and promoted connectivity restoration across the injury spinal cord site,” according to the findings. “These effects translated to substantial functional improvement, enabling paraplegic rats to walk independently and regain sensory perception.”
The study, led by Dr. Shulamit Levenberg, the dean of the Technion’s Biomedical Engineering Department and the president of the Israel Stem Cell Society, and Dr. Daniel Offen, the head of the Neuroscience Laboratory at Tel Aviv University’s Sackler School of Medicine, was published in the magazine Frontiers in Neuroscience late last month.
The study consisted of an initial 53 rats divided into four groups: one group that underwent surgery and was not treated with the construct or cells, a second group implanted with just a scaffold and no cells after surgery, a third treated with a scaffold and naive (untreated) cells and a fourth with a scaffold with cells induced into a neural phenotype. The scientists surmised that the latter would be a device “capable of enhancing endogenous regenerative processes and promoting neurological recovery following complete spinal cord transection.”
After some three weeks, according to the experiment, the rats treated with the induced tissue-engineered constructs “demonstrated higher motor and sensory recovery when compared to all other groups” with 42 percent of the animals demonstrating “consistent weight support of the hind limbs and statistically significant improvements in walking abilities.”
The gait and coordination analysis of the rats “revealed walking patterns similar to those of intact rats, with progressive and adaptive motor coordination over time,” the scientists said.
In addition, 75 percent of the rats treated with the induced constructs showed significant improvement in sensory responses to gross external stimuli almost two months after the implantation. Rats in the other three groups failed to show these responses.
The rest of the rats in the group with the induced construct showed no response and the researchers said that aspect required further investigation.
Dr. Levenberg said that while researchers were able to rehabilitate a damaged spine using stem cells, this particular study marked “the first time that the transplantation of stem cells was able to significantly impact sensory perception in limbs and complex mobility, including walking, in just a few weeks,” as quoted in the Israeli daily Haaretz.
She tells NoCamels that the technique used for the transplantation, that is the combination of the 3D construct and the stem cells — was unprecedented and that the most surprising aspect was how the animals with the induced constrcut “were walking almost completely normally.”
Dr. Levenberg says that there is still a lot of research to be done, and careful clinical trials to be conducted until the experiment could be applicable to humans, “but the potential is there.”