Since several decades, medicine doctors have constantly Â improved organs draft methods. Nowadays the results are impressive : less rejects, less complications and less invasive surgeries for patients. However a problem has not changed : the lack of donors. Indeed this factor is independent from medical research and it is not going to change in the next few years. This means that the number of organ to draft will stay the same. A second problem is compatibility. The donor is not always compatible with the recipient. The given organ will then be rejected since it will be detected as foreign (see more information about draft here).
Nowadays, another approach is rising. The first artificial heart was built by a french company : CarmatÂ® (http://www.carmatsa.com)Â and drafted by a french medical team. This was a great improvement but the organ has to be developed with special materials that will not be considered as foreign, which is very difficult. Â To overcome this difficulty, researchers are working on new ways to “grow” organs with cells. This is called 3D cell culture.
The idea is to recreate the complete environment of the different groups of cells and to add some growth factors. This way, cells will grow naturally in the same manner than in the human body. Thus, it is possible to create a complete tissue and then, a entier organ. TheÂ problem of compatibility is not a problem anymore because it is possible to begin with cells taken from a compatible donor or even more interesting, from the recipient himself. This week, an american research team coming from the Wisconsin announced having grown vocal cord in vitro in their laboratory. The main question is : are these vocal cord able to work? The answer is yes, and this is why this achievement is a great accomplishment for them, coming after many years of experiments. More particularly, in vocal cords mucosa’s folds located near the larynx are very difficult to reproduce in vitro. These folds determine the function of these vocal cords since they have to vibrate when air goes through.
Mucosa was created from human epithelial cells purified and put on a tridimensional collagen matrix. This matrix allows to give a shape to the culture and to grow the tissue in all the directions, the same way as it is supposed to happen naturally. Â After having obtained these vocal cords, researchers have drafted them to mice having a special immune system (allowing a human draft). The same thing was made on dogs and the sounds that were obtained were similar to barking sounds. Â No reject have been observed during these tests, which means a duration of three months.
What an achievement, you will say. But there is still lot to do. Indeed the artificial vocal cords architecture is much simpler than the one of the native ones. Scientists will need many years more to produce the same complexity for their artificial vocal cords. Eventually thisÂ improvement give a good hope for treatingÂ patients having lost their voices after a surgery or a disease.
PhD Student in Biophysics