Positrons (anti-electrons) are already used to detect cancerous tumors. It is possible that antiprotons will be used in the future to eliminate them
Antimatter is a concept particularly beloved by science fiction creators: take for example the matter-antimatter propulsion of the spaceship Enterprise. However, despite its strangeness, the antimatter is not fictional and its effectiveness has even been proven in medical uses: positrons, which are used in positron tomography (PET) - a mapping technique used, among other things, to identify cancerous tumors - are the antimatter of electrons.
But researchers working at CERN, a large elementary particle laboratory located near Geneva, now have much bigger ideas. They discovered that another type of antimatter, the antiproton, may not only locate cancerous tumors but also help eliminate them.
The positrons used in PET scans are created by the decay of radioactive chemicals. They are injected into the patient's body, accumulate in the cancerous tumor cells and allow them to be identified. The antiprotons are much more difficult to produce. To do this, targets made of metals such as tungsten need to be "bombarded" with ordinary protons. In some cases, the energy released as a result of the collision turns into matter - an additional proton and an accompanying antiproton. The antiprotons produced in this way must be transferred to another accelerator so that they can continue to move in a vacuum (if the antiprotons collide with something made of ordinary matter, the encounter between them and the ordinary protons will result in their destruction).
One place where antiprotons can be produced in this way is the CERN laboratory. In the laboratory there is a multidisciplinary collaboration between several universities and companies. One of the companies, "PBar Laboratories" from California, is testing how antiproton beams behave when they are launched into living cells.
As expected, the researchers discovered that the antiprotons remove the electrons from the atoms in the cells - a process called ionization. Ionization breaks up the molecules containing the atoms, which often results in the destruction of the cells. The process of course destroys all types of cells, not just the cancerous ones. But if the energy of the antiproton beam is carefully chosen, it can burn a tiny hole at a specific point deep under the skin. This means that the beam can be aimed precisely at a cancerous tumor.
So far, the described process does not differ from the action of a beam of ordinary protons. Given that antiprotons are much more difficult to produce and store than regular protons (which can be produced by hydrogen ionization), it is not clear what their inherent benefit is. But still there is a difference. When an antiproton uses up its energy it continues to move in no preferred direction. When it encounters an ordinary proton, everything goes out of control: the proton and antiproton annihilate each other, which causes the release of an enormous amount of energy (in terms of a single cell). This process causes a lot of damage, which is why it is much more effective for killing cells than ionization.
Experiments recently completed by the team of researchers at CERN confirm this picture. However, the researchers, Michael Holzscheiter and Karl Majura from PBar Laboratories, emphasize that these are preliminary experiments that will need to be repeated to prove that the initial results were not accidental. The researchers will also need to make detailed comparisons with similar experiments, where ordinary protons are used. The purpose of these experiments will be to confirm that the antiprotons do indeed cause more damage than the normal protons.
Even if the results prove beyond any doubt, there is a difficult question of the cost of the process. Will it be possible to make the production of the anti-proton rays economically viable so that they can be used as a treatment for cancerous tumors? CERN is only one of a handful of laboratories in the world where such beams are currently produced. Because of this, Dr. Holzscheiter and Dr. Majora think that only in ten years it will be possible to develop routine clinical applications of these rays. Eventually, they hope, the antiprotons will be just as effective for medical uses as the positrons.
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What is certain is that in the end they will make a weapon out of it...