Biotechnologists at Harvard University have successfully created the world's first artificial bionic limb of a rat by growing its muscles, blood vessels and other components from stem cells, according to an article published in the journal Biomaterials.
“Our limbs contain muscles, bones, cartilage, blood vessels, ligaments, nerves and other things, each of which has its own 'skeleton' that supports their shape. We have shown that we can preserve them in the form and position in which they are in the arms and legs, maintain them in this state for an infinitely long time and use them to re-grow, at least, vessels and muscles,”said Harald Ott (Harald Ott) from Harvard University (USA).
Ott and his colleagues have been working on artificial versions of damaged organs for several years. Two years ago, they created an ingenious technique that allows them to grow healthy copies of the kidneys, using the diseased organ as a "scaffold" for stem cell growth.
In Ott's technique, the damaged organ is first treated with a combination of chemicals that destroy cells and leave the junctional proteins that surround them. Then this "template" is filled through the former arteries and urinary tract with "blanks" of kidney and vascular cells extracted from the rat embryo. Artificial lungs, heart, liver and several other organs were grown in a similar way.
Using this technique, Ott's group prepared a rat leg scaffold and tried to use it as a template for a bionic limb. Scientists did not set themselves the original goal of growing the entire leg, and therefore focused their attention on the two heaviest parts of the limb - the muscles and blood vessels.
By placing the "skeleton" and a set of stem cells of muscles, blood vessels and connective tissue in a special bioreactor, the scientists obtained a full-fledged limb in a few weeks, with the exception of the nerves missing in it.
To test the leg's performance, scientists connected electrodes to its muscles, which caused the limb to contract when current was applied. The fingers, joints, and individual muscles of the artificial leg moved successfully and, according to the authors of the article, they had comparable strength compared to the limbs of a newborn rodent.
Promotional video:
Now scientists are trying to grow an artificial primate arm in the same way, using the amputated limb of a baboon as a "frame", and are also thinking about how to solve the problem with the germination of nerve endings in the limb.
According to Ott, this problem can be solved on its own.
“In clinic-based limb transplants, nerves often grow from the stump into the implanted leg or arm, which allows the patient to feel and move them, and we have found that this recovery process is also dependent on the 'scaffold'. We hope that in the future we will be able to use this feature of the body when creating full-fledged artificial limbs,”the scientist concludes.