Russian and Finnish physicists created a new type of silicon nanoparticles that can be used for cancer tumor destruction by heating to extreme temperatures as well as for measurement of temperature inside an organism. This statement was made by RIA Novosti Agency on May 31, 2017. The researchers published their article in Nano Letters Journal.
In the last few years several fundamentally new methods of the cancer treatment using nanoparticles were developed. In some of them nanoparticles are instruments that help to destroy the tumor. They act as a 'target', on which the immune cells or laser beam that heats the nanoparticles and burns the tumor cells, are directed. According to George Zograf, the leading author of the investigation (Department of Nanophotonics and Metamaterials, Saint Petersburg National Research University of Information Technologies, Mechanics and Optics), in most cases for this purpose the spherical nanoparticles of gold and some other metals are used. They absorb the light and infrared rays and convert it to the heat. However, these nanoparticles have a disadvantage - because it is impossible to measure their temperature, such nanoparticles can destroy not only cancer cells, but also healthy cells near them. Moreover, the nanoparticles of some metals are toxic.
It turned out, that the spherical silicon nanoparticles don't have this disadvantage. Their absorption spectrum changes with the heating and the particles decompose easily in the organism. The researchers succeeded in heating the silicon nanoparticles to 900 K by the red or infrared laser irradiation. At the same time they could record the changes in heating of nanoparticles right until they reached the melting temperature.
Moreover, it turned out that the silicon nanoparticles convert light to heat up to 4 times more effective compared with similar gold nanoparticles. This fact will allow decreasing the laser power, and thus protecting the healthy tissues from damaging, and also will make the cancer treatment more reliable owing to the possibility to control easily the temperature of heating the particles by changing the wave length of laser.
According to the researchers, besides cancer treatment, such nanoparticles could be also used, for example, for increasing in the rate of chemical reactions, in temperature-sensitive elements, or as a part of some other nanodevices.
Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (http://www.ifmo.ru/ru/) was founded in 1900. Its priority directions are information technologies, photon technologies, quantum communications, robotics, translational medicine, urban planning, art and science, science communication.