The researchers show porous silicon nanoparticles could be harmless to diagnose and treat cancer -
Researchers from the State University Lomonosov Moscow, together with their German colleagues were able to demonstrate that silicon nanoparticles can be applied to diagnose and treat cancer. For the first time particle's ability to penetrate the diseased cells efficiently and completely dissolve after drug administration was shown. Details of the research are presented in the article published in the latest issue of Nanomedicine: Nanotechnology, Biology and Medicine . http://dx.
Scientific management team is called theranostics. This term means a "therapy" and combined "diagnosis", referring to the process of detection and treatment of concurrent illness. One of its applications is a range of spotting oncological diseases, with the help of filled nanoparticles of drugs for their targeted delivery in a cancer cell. Today, many of these nanoparticles does not meet the requirement of biocompatibility. According to researchers, Liubov Osminkina (Senior Researcher, Physics Department of Lomonosov Moscow State University), some nanoparticles can act quickly, accurately deliver the drug, cure a number of diseases, but months later, a patient may suffer from liver, kidney, lung pain, or even headaches.
"The reason is that gold, silver, titanium oxide, cadmium selenide and many other nanoparticles are excreted almost no, 'says Liubov Osminkina. "When the nanoparticles into the bloodstream, they can jam in the internal organs and after a while they begin to harm the body due to prolonged toxic effects.
Search not only biocompatible, but also biodegradable transportation to a delivery scientists targeted drugs noted porous silicon. Its nano-particles certainly would not hurt, can help the body instead, following their dissolution is silica, vital for bones and connective tissues.
These nanoparticles have been the main concern of Liubov Osminkina when she received the DAAD-MSU "Vladimir Vernadsky" grant in 2013 (a joint research program with Moscow State University and the exchange DAAD German academic service) to synthesize nanoparticles of photoluminescence of porous silicon nanowires to Theragnostics. She went to Jena, the Leibniz Institute of Photonic Technology one of the main scientific directions of what is Biophotonics - the use of optical techniques for the study of living systems. The special attention of a young employee of the Moscow State University has focused on the micro-Raman spectroscopy.
Raman spectroscopy is based on the ability of the molecules to a so-called inelastic scattering of monochromatic light which is accompanied by a change in its internal state and changes in the frequency response of the emitted photons. This type of spectroscopy distinguishes the relative simplicity and abundance of information obtained - enough to illuminate a material with a laser and analyzing the radiation spectrum. micro-Raman spectroscopy has been used at the Institute of Photonic Technology, among many other optical methods. With his help, the scientists analyzed the contents of a living cell and comparing the spectra obtained lined up a picture of what and where is located inside the cell.
'That's when I came up with an idea to conduct a nanoparticle biodegradation study using micro-Raman spectroscopy, "explains the scientist. "This technique allows not only to locate the nanoparticles in the cell (the signals from the silicon and cell components have different frequencies), but also to monitor the process of their disintegration. This was possible because, as we know, the Raman spectrum of silicon nanoparticles depends on their size - the smaller they are, the more spectrum becomes, the move to lower frequencies
In after the study of the grant, Osminkina won another MSU-DAAD grant was for the implementation of its new ideas - and she went to Jena again. The essence of the new study Osminkina and colleagues came from the fact that breast cancer cells were incubated with 100 nm in size silicon nanoparticles, and in particular with the micro-Raman spectrometer, the scientists have observed what happens in the cells during different periods of time from 5 hours to 13 days. Given the Raman spectrum and the reconstructed images of the particles and the cells that they have seen how, during the first 5-9 hours nanoparticles are localized on the cell membrane and enter the cell during the next day, and then begin to biodegrade, as evidenced by a decrease in the amplitude of the signal, the spectral broadening and the appearance of the peak of the amorphous silicon phase. It has been shown that the 13th day the nanoparticles dissolve completely and the signal disappears.
"Thus, for the first time we have shown that porous silicon nanoparticles could be completely Theragnostics harmless agents for many types of cancer. They do not only penetrate easily into the diseased cell, but when filled with the drug, may be issued for their dissolution. I believe the results of our work are of great importance in the long term as the basis for creating drugs based on biocompatible and biodegradable silicon nanoparticles, says Lubov Osminkina.
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