Follow
A team of scientists at the Massachusetts General Hospital took the first step towards creating replacement limbs which can be used for transplantation. The paper was published in the journal Biomaterials.
More than 1.5 people in the US have lost a limb. Although prosthetic limbs have an improved appearance and performance they still have limitations. And patients who receive hand transplants from donors risk lifelong risks because of the immunosuppressive therapy. Fortunately this problem may be solved thanks to this new discovery.
Instead of relying on a donor, in the future patients could use their own progenitor cells in order to regenerate the tissue for a new limb. A trial conducted on mice showed that the biological nature of our limbs can produce functional replacements. However in the case of humans things are more complicated.
The research team led by Dr. Harald Ott from the Massachusetts General Hospital Department of Surgery and the Center for Regenerative Medicine tripped away cellular material from the deceased rats’ forelimbs over a period of one week. They preserved the nerve matrix and the main vasculature. Afterwards the researchers used to bioreactor to populate the forelimb matrix with vascular cells and cultures of muscles. To regenerate the veins and the arteries the main artery of the limb was injected with vascular cells, whereas the progenitor cells were injected in the matrix for the position of the muscles.
In order to encourage muscle formation the researchers electrically stimulated the limbs after five days. The limb was taken out of the bioreactor after two weeks and the researchers observed how the new muscle fibers indeed contracted and in addition the strength was 80% that of a newborn rodent. Finally when the forelimbs were transplanted to the recipient rat blood began to circulate in the new limb and when electrically simulated the digital joints and the wrists of the paws flexed.
Although the experiment was successful this procedure is complicated when it comes to humans because human limbs contain bones, muscles, tendons, cartilages, ligaments, nerves and blood vessels. All of these must be rebuilt part by part.
Dr. Ott remarked:
“In clinical limb transplantation, nerves do grow back into the graft, enabling both motion and sensation, and we have learned that this process is largely guided by the nerve matrix within the graft.”
The net step the team will take is to apply the same principle in muscle regeneration using human cells and probably in the future the research will be extended to human bone, tissue and cartilage regeneration.
Image Source: Press TV
