For decades, scientists have been searching for ways for regenerative medicine to restore movement in patients who've suffered traumatic spinal cord injuries. Unfortunately, due to limitations, stem cells have always been rejected during transplants.
But now, a ground-breaking stem cell study has shown promise in restoring movement in injured monkeys, allowing them to grasp objects.
Axons are the neuronal branches the brain employs to communicate with the rest of the body. When there's spinal cord trauma, axons are essentially cut off from the brain. In order to restore motor function, the lines of communication between the axons and the brain must be regenerated.
A crucial road block however, is that the spinal cord quickly reorganizes the extracellular matrix around the damaged site after the spinal trauma. These proteins prevent transplanted stem cells from extending outside the axon branches. Growth factors which act as protective cocoons for stem cells are also missing from the injured site.
Scientists conjured up growth-promoting concoctions, as to give the transplanted stem cells some add regenerative oomph during the procedure. The team was able to transform skin cells from a healthy human donor, and transform them into induced pluripotent stem cells (iPSCs). IPSCs are derived from skin or blood cells that have been reprogrammed back into an embryonic-like pluripotent (capable of giving rise to several different cell types) state.
The iPSCs were embedded into a matrix containing growth factors, and grafted into rats with two-week-old spinal cord injuries. While the human cells matured into new neurons and extended axons along the rats' spinal cords, there was no improvement in function because of scarring at the transplant site.
Undeterred, the researchers continued their stem cell study, and turned their attention to monkeyswhose spinal cords offer a similar model to that of humans.
The team cut into a section of the monkey's spinal cord, then grafted human stem cells into the injured site along with their souped-up growth factors. Initially, the grafts didn't stay in place, and the researchers came to the conclusion that they needed to intensify the amount of a particular protein ingredient in their recipe. The idea was to better "glue" the graft in place.
They tilted the surgical table during the transplant to stop cerebral spinal fluid from washing out the graft. In order to neutralize the body's propensity for attacking human cells, the monkeys were given a bigger dose of immunosuppressive drugs.
The grafts stayed in place in the remaining monkeys. Each graft contained approximately 20 million neural stem cells.
The team discovered a drastic increase in new neuronal branches after two months. The stem cells grew into mature neurons, cultivating 150,000 axons along the monkey's spinal cord. Some neuronal branches traveled the length of two human spinal cord fragments (50mm) from the graft site. They connected strongly with the monkeys' undamaged cells.
Then, the monkeys' own axons developed synapses with the human neural graft, forming the reciprocal connections crucial to voluntary arm movements in humans.
After nine months, the new neural connections helped the injured monkeys regain limited movement in forelimbs. The subjects regained the ability to grasp soft, squishy objects at will, whereas the monkeys with failed grafts had little control over fine movements in their palms and fingers.
Stem cell therapy and regenerative medicine are truly incredible. We'd know, because although RegenerVate may not be embarking on ground-breaking spinal cord treatments, we apply the vast healing properties of stem cell therapy every day, utilizing our clients' own blood and fat to facilitate the expedited natural healing of tears, tweaks, strains, and other forms of chronic pain.
|Tags: Stem Cell Research|