Nanoparticles for medicine
Such foci cannot be seen with the help of X-rays, ultrasound scanning or magnetic resonance imaging.
However, the situation is not hopeless. Cancer cells synthesize specific proteins that are absent in normal cells of the same organs. These proteins are secreted into the blood and circulate through the bloodstream – however, in very small quantities.
In recent years, many experimental techniques have been created to detect tumor proteins at the earliest stage of the disease. They have not yet entered mass medicine, but oncologists predict a great future for them.In order to catch abnormal biomolecules, they must be connected to some sensors that can inform the recording equipment about the fact of this capture.
Specially grown antibodies with selective chemical affinity for a particular tumor protein are well suited for this. They can be additionally loaded with molecules of fluorescent pigments, which are activated after the antibody binds to the protein. When this happens, the antibodies become sources of a faint glow, which can be detected using photodetectors. Such methods of hunting for freely circulating cancer proteins have been improving for several years.
Now scientists from Stanford University, led by Professor of Materials Science and Electrical Engineering Shen Wang, have proposed another version of this method, which is based not on optical, but on magnetic registration of antibodies with cancer proteins.
They label antibodies with nanoparticles made of highly magnetic materials. When combined with a protein, the antibody rearranges its spatial structure, which affects the configuration of its magnetic field. Such changes can be noticed with the help of precession magnetic field sensors based on the effect of giant magnetoresistance.
According to a report from Wang's laboratory published in the Proceedings of the National Academy of Sciences, the sensitivity of this method is about a hundred times higher than the sensitivity of fluorescent registration. This means that the new technology makes it possible to detect cancer proteins in much lower concentrations. Professor Wang also believes that magnetic detectors of cancer cells in mass production will be much cheaper than optical ones.
Another technique of using nanotechnology is dental polishing against bacteria. By eliminating the smallest irregularities of the surface of the teeth, it is possible to successfully prevent the decay of dental tissue.
Employees of Clarkson University in New York State have proposed a new method of caries prevention. This more than a massive disease occurs as a result of the vital activity of some bacteria that are always present in the plaque on the surface of the teeth.
Under the influence of these microorganisms, sugar breaks down and acid is formed, which dissolves calcium, which is part of tooth enamel. At the same time, the microbes responsible for caries (usually from the group of streptococci) nest best in the irregularities of the dental surface.
Professor of Physics Igor Sokolov and his graduate student Ravi Gaikvad decided to make it difficult for the harmful inhabitants of the oral cavity to live on the dental surface. They have developed a technique for ultra-fine polishing of teeth using liquid suspensions of quartz nanoparticles, which are used for similar purposes in the semiconductor industry.
It turned out that this treatment allows you to perfectly smooth out the dental surface, removing all irregularities larger than a few nanometers.
As a result, the enamel becomes so "slippery" that the bacteria cease to stay on it and are easily removed with the help of a banal washing with ordinary water. This post was published by the Journal of Dental Research.
(The picture shows the tooth surface before and after polishing.)
Professor Sokolov told the Russian service of the Voice of America that he conducted his experiments on milk teeth removed from children. He noted that, in principle, it is possible to process teeth directly in the mouth in the same way. Dentists have been doing this for a long time, but their methods do not allow polishing the enamel to the desired degree of smoothness.
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