Scientists at the University of California, San Diego (UCSD) School of Medicine have successfully restored motor function in paralyzed rats by grafting human spinal stem cells (hSSCs) in them.
"We demonstrated that when damage has occurred due to a loss of blood flow to the spine's neural cells, by grafting human neural stem cells directly into the spinal cord we can achieve a progressive recovery of motor function," said lead researcher Dr. Martin Marsala, Professor of Anesthesiology, whose study has been published in the journal Neuroscience.
"This could some day prove to be an effective treatment for patients suffering from the same kind of ischemia-induced paralysis," he added.
The researchers are currently testing the safety and efficacy of human stem cell therapy in other animal models, and may begin clinical trials in humans by next year.
Sixteen rats were induced spinal cord ischemia during the study, and then they were injected with with human spinal stem cells 21 days after paralysis. The researchers also injected seven other rats with with medium that did not contain stem cells.
They found that three of the nine rats injected with hSSCs returned to walking at six weeks, and three others had improved mobility in all lower extremity joints. All nine animals achieved significantly better motor scores than those in the control group, and showed a consistent presence of transplanted cells in the spinal area.
It was also seen that the majority of transplanted human spinal stem cells survived, and became mature neurons, according to Marsala. The researcher revealed that a second study conducted over a three-month period also furnished similar results.
The researchers believe that the therapy may eventually prove even more effective in human patients.
"Physical therapy may accelerate integration of the grafted stem cells and enhance their therapeutic benefit," said co-author Karl Johe, a researcher at Neuralstem, the company that manufactures the hSSCs used in the study.
The researchers say that their main goal is to provide a significant gain in functional mobility of the patient's legs.
"These research findings could offer great hope to people with spinal ischemic injury who suffer from resulting spasticity and rigidity," said Marsala.