A quarter of a million people in the United States suffer from various forms of paralysis due to spinal cord injuries. The most famous of these was the actor Christopher Reeves, who spent the last years of his life campaigning for research into curing spinal cord injuries. The popular media has suggested that stem cells
hold the most promise for curing spinal cord injuries and thus restoring movement and other functions for people who would otherwise remain confined to a wheel chair for the rest of their lives.
Pavla Jendelova, a researcher at the Institute for Experimental Medicine in Prague, the Czech Republic, has developed a method of treating spinal cord injuries that has had great success in rats. Jendelova presented her findings at a recent molecular medicine conference at the Cambridge Healthtech Institute in San Francisco.
Jendelova’s method for treating spinal cord injuries involves building a bridge across the injury using am implant made of hydrogels, a jelly like polymer made up of latticed networks of amino acids. This “bridge” resembles the soft tissue that surrounds the spinal cord as it develops in the womb.
Next, stem cells are injected into the implant and are allowed to grow into neurons, thus bridging the gap created by the injury. Eventually these stem cells would repair the breach created by the spinal cord injury, thus restoring movement and functionality to the patient.
The team at the Institute for Experimental Medicine induced spinal cord injuries in twenty eight rats. Then they implanted the hydrogel bridge, permeated with the stem cells, across the gap created by the injuries.
Four weeks later the rats were examined. The stem cells had successfully created spinal cord material, reconnected the two parts of the injured spinal cords. The rats had recovered a great deal of limb functionality that had been lost due to the original spinal cord injury.
The natural question arises, when will this treatment for spinal cord injuries be available for humans? A great deal of research must be conducted and regulatory hurdles must be surmounted before injured people will be able to walk. Ethical concerns about using embryonic stem cells as opposed to those derived from adult cells have to be addressed. The human spinal cord is much more complex and ten times thicker that that of rats. Also, the human immune system might reject the new implant. Recent experiments with pigs, though, suggest that the method may scale up nicely.
Human trials will likely begin within the next five years. If the trials demonstrate favorable results, the first people to benefit will be those who have had recent spinal cord injuries. Eventually it is hoped that even those who have suffered for years or decades from spinal cord injuries could have some function restored.
Even if the treatment method being studied at the Institute for Medical Research does not pan out, several other methods of curing spinal cord injuries are being looked at around the world. Hans Keirstead at the Reed-Irvine Research Center, for example, is conducting trials for a method that would treat patients with recent injuries, inhibiting the loss of tissue in a spinal cord injury and making it less likely that a person would suffer paralysis as a result.
It may well be that in the near future, within a decade, the lame will be able to walk again and that injuries that would previously condemn someone to a lifetime in a wheel chair will be treatable. Such is the promise held out by this kind of research.