OREANDA-NEWS  Chemists from St. Petersburg ITMO University have created unique nanoparticles-transformers that change their structure when illuminated by a laser, which allows them to be used to fight tumors. Their description was presented in the journal Bioconjugate Chemistry.

"This direction is interesting not only for the delivery of drugs, but also to create a computer in which instead of conventional silicon chips biological molecules will be used. This will open the way for high – precision control of chemical processes, "smart" drugs and control of molecular machines," said Ekaterina Skorb from ITMO University in St. Petersburg, whose words are quoted by the press service of the Russian science Foundation.

Foreign and Russian scientists are increasingly experimenting with various nanoparticles to fight cancer, infectious diseases or for the treatment of noncommunicable diseases. Typically, they are used for the delivery of dangerous toxins into the tumor or the site of infection.

In other cases, nanoparticles help to remove tumors and destroy microbes and viruses. They are attached to them and play the role of a target for immune cells, or become a target for a laser beam, heating particles and burning cells.

Scorb and her colleagues combined the best properties of these two types of nanoparticles, experimenting with a light-sensitive nanomaterial, a kind of chemical "switch" that they discovered relatively recently.

It consists of titanium dioxide nanoparticles capable of splitting water into atomic oxygen and hydrogen when exposed to light. If such particles are placed in a solution of organic compounds, the oxygen produced by them will interact with the most vulnerable molecules, which will lead to a sharp change in the acid-base balance.

Scientists wondered if this nanomaterial could control the behavior of larger nanoparticles. For example, they can be assembled from "switches" and molecules, whose stability varies greatly with the fall or increase of the pH level, which will "open" or "close" such nanoparticles under laser illumination.

Guided by this idea, Scorb and her colleagues created hollow nanoparticles, with a shell of polymer filaments and inclusions of titanium oxide and silver. If they are illuminated by an infrared laser, the whole structure will collapse under the influence of heat and oxygen, which will release its contents.

The work of these nanoparticles, scientists have tested for bacteria. Their DNA was modified in such a way that these microbes began to glow when molecules of one of the artificial sugars got inside them. Starting nanoparticles that sugar, chemists from the University have tested whether E. coli to glow, if I highlight the tube an infrared laser.

Experiments have shown, such "nanograde" coped with its task, bringing the sugar inside bacteria. At the same time, neither the particles themselves nor the process of their destruction affected the viability of the cells.

The ability to interact with infrared radiation, according to Sorrows, will be another additional plus – the human body is almost no barrier to such rays, which will allow the use of nanoparticles to combat tumors and infections in almost the entire body.