Silicon nanoparticles against cancer
Russian scientists have developed a method for encapsulating and releasing drugs from nanocontainers for local therapy of oncological diseases
Tatiana Perevyazova, Press Secretary of ITEB RAS
It is known that the chemicals with which doctors fight malignant tumors are very toxic to the rest of the body. Unfortunately, it often happens that cancer clinic patients, even having overcome cancer, cannot cope with the consequences of the treatment itself. Therefore, for several decades now, many scientists from all over the world have been looking for ways to treat cancer that are not so detrimental to the whole body as a whole. One of the methods of local delivery of the drug directly to tumor cells was developed by Russian scientists from Moscow State University, MEPhI, the N.N. Blokhin Russian Cancer Research Center and ITEB RAS, in collaboration with their colleagues from Finland. The result of their work (Tamarov et al., Temperature responsive porous silicon nanoparticles for cancer therapy – spatiotemporal triggering through infrared and radiofrequency electromagnetic heating) is published in the Journal of Controlled Release, impact factor 7,441.
The development proposed by scientists is based on the use of biocompatible and biodegradable silicon nanoparticles. They are permeated with multiple pores, due to which they are able to literally absorb various substances. A drug is injected into the nanoparticles, the effect of which is aimed at the death of tumor cells. Further, researchers use the property of malignant tumors to accumulate inside themselves any inclusions that may be in the body even in negligible amounts. But a problem arises: as long as the nanoparticles make their way to the location of the tumor, drugs can be lost, leaving the pores. In order to prevent this process, nanoparticles are coated with a thermosensitive polymer.
After such "sealed" nanoparticles are introduced into the tumor, the drug is "released" as a result of changes in the properties of the polymer when heated to temperatures above 37 0 C. "Nanoparticles with an antitumor drug were injected into the culture of tumor cells," says one of the authors of this work, a leading researcher at the laboratory of cytotechnology and the laboratory of tissue Engineering Andrey Alexandrovich Kudryavtsev of the Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, – "after that, we subjected nanoparticles to either electromagnetic or infrared irradiation. Under these conditions, the temperature of the samples increased, the polymer coating shrank, releasing the active substance from the pores."
In their experiments, scientists have demonstrated that when using such a coating for nanoparticles, the effectiveness of antitumor drugs increases many times. Researchers have shown the effectiveness of this method of treating malignant tumors not only on cell cultures, but also on living organisms. After a single injection of a polymer-coated nanoparticle system carrying antitumor drugs for the treatment of mice with a grafted tumor in combination with electromagnetic radiation, there was a clear suppression of the growth of carcinoma and prolongation of the life of the tested animals.
Another advantage of the proposed treatment method is the biodegradability of porous silicon nanoparticles, which can be excreted from the body naturally. Thus, porous silicon nanoparticles can be used in biomedicine as a method of local delivery of drugs for the treatment of malignant tumors.
In the future, the researchers plan to optimize the main parameters of their proposed method. Apparently, such therapy will consist of several repeated cycles of the introduction of nanoparticles with an antitumor drug and electromagnetic irradiation to initiate the release of an antitumor drug. In addition, researchers need to choose the most suitable properties of nanoparticles, such as, for example, their size, concentration, dose of administration into the body to achieve the main goal – complete removal of a malignant tumor.
The work was carried out with the support of the RPF grant No. 16-13-10145
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24.01.2017