ARTIFICIAL ORGANS – The bionic man (part 1)
It is not science fiction, despite appearances. Rebuilding parts of the body man missing at birth or lost as a result of an accident, or Cancer is not only an inspiration to the writers of Star Trek, but for researchers from around of the world who already have at hand a handful amazing project based on serious scientific evidence.
Organ is no longer a novelty. Surgeons carry some 30 years so and, today, has become so common that the biggest obstacle to reinstate organs such as kidneys, heart or liver is not surgical technique itself, but the shortage of donors. Advances in Cell Biology, Genetic Engineering, in the manufacture of plastic materials and microelectronics portend a real future in which organs and tissues may be manufactured as, instead of moving from one body to another, in order to regain past form, for example, a breast mastectomy, an arm amputee, or even as sharp as structures an ear or a nose.For the moment, and until that manufacturing is about, scientists remain investigating, in parallel, other ways to replace the function of the lost organs. There is no doubt that devices such as dialysis or machines that replace the heart and lungs have been able to improve perspectives of patients who otherwise would have had a fatal destiny. But these teams, which are sophisticated, they are not perfect and often worsen the quality of life of the individual who has to spend the rest of his days attached to a machine. Another area being investigated and could provide a short term solution is to xenotransplantation (use animals as organ donors).
Researchers have long try to find animals that have tissue compatible with the system to avoid human immune rejection in transplantation. Moreover, they are looking for new drugs such as cyclosporine, are able to “force” defense system to accept organs from other species. Microelectronics is another solution that can serve as a bridge between the old and new technologies, helping to replace all the functions sensory, or otherwise, that go away after an illness or amputation. For example, this year will be in the market prosthesis arm could feel the heat and cold. Members had already been achieved artificial feel pressure, and now it has fallen to the temperature. In the fingers of the artificial arm sensors are placed and “Feelings” thermals to travel to a circuit receives computerized interprets them and sends them to electrodes that are in the skin, nerves, Muscles and bones are not amputees, and thence to the brain. Another example is the magnetic heart being designed models each smaller and has no other function than to make people heart failure lead lives as normal as possible, freed from machine that now holds them.
The biosensor for diabetics as clocks is another device that is benefits of microelectronics. It has been created to detect the levels of glucose in these patients and may then disappear soon syringes of their lives, because it also serves to administer the required dose of insulin. The invention described, which appeared a few months ago in Scientific American and in Nature Medicine and will be tested first in clinical trials middle of this year, is based on the fact that the permeability of the skin increases with certain electric fields or ultrasonic waves of low frequency. This allows sugar levels can be measured in the minilab of bracelet, with the help of an enzyme such as glucose oxidase or sensor optical, and, with equal ease into the blood the same amount of insulin. Diabetes occurs when the pancreatic islets, which are producers insulin, are destroyed or not produced enough of the hormone. And just what is being attempted, so with this watch for diabetics as with other devices with the same function but which are implanted under the skin-is replace the pancreas.
According to Robert Langer, professor of biomedical engineering at the Institute of Technology in Massachusetts, Joseph P. Vacanti, director of the Laboratory Transplant and Tissue Engineering at Children’s Hospital at Harvard, other Possible substitutes might be small reservoir of insulin and glucose oxidase, made from plastic semipermeable matrices are implanted in different parts of the body of the diabetic. When blood sugar rises, react with the enzyme glucose reservoir, generating an acid product that either alter the matrix permeability or solubility of the hormone that leads inside, and that in either case, increased insulin release bags.
The only drawback is the scientists who see the stores of the enzyme and hormone would be filled from time to time. Clearly the ideal replacement would be neither the clock nor the reservoir, but one that carried healthy cells of pancreatic islets, but as the donor shortage, is being investigated not only the possibility of using pancreatic tissue of animals, but something more exciting: making tissue from cells that multiply outside the body and is later implanted in the patient.
Langer and Vacanti, who have over 20 years working on problems organ implants, no doubt that the future of tissue reconstruction depend on biodegradable plastics and polymers. The computer designed to be responsible for the three-dimensional shape structures that are lacking and these polymers are the material basis for rebuild tissue and even the lost organ. The idea is that these plastics do scaffold function or structure support for “seeded” with cells for tissue or organ in question, and that polymers are capable of guiding cellular growth until configure the shape of the desired member. This structure has to deal with special compounds for cells will stick together and multiply. And as the cells are proliferating, the plastic will degrade and eventually leaves only the tissue true, ready to be implanted in the patient. It’s similar to what has already been done with human skin to replace it in the burned individuals. It has also been tested on animals. Recently achieved create artificial heart valves lambs from cells extracted from the blood of these animals. And this is proof that the cells communicate with each other in the same way they do in utero, organizing the growth and rebuilding the original tissue. Researchers believe that this same technique could be used to reconstruct functional organs intact, but, despite the evidence from the study of heart valves, no one knows yet if he could grow an organ from a few cells in culture. Although scientists are convinced that yes. “Surgeons would only have to worry about adjusting the connections of the organs to nerves, blood vessels and lymphatic channels of the patients “, say Langer and Vacanti.
credit to: MYRIAM LOPEZ BLANCO