Nanocrystals, special plant proteins and tumor treatment: developments of young scientists

Methodological platform for reproducible synthesis of nanocrystals

Whisker nanocrystal (NWC), often calledalso nanowhisker (from the English nanowhisker) or nanowire, nanowire, as well as a nanorod is a one-dimensional nanomaterial, the length of which significantly exceeds other dimensions, which, in turn, do not exceed several tens of nanometers.

There are different types of NOCs,

among which are metal, semiconductor (for example, from Si, InP, GaN and others), molecular (consisting of molecular units of organic or inorganic origin) and others.

There are several fundamentally differentmechanisms for obtaining one-dimensional nanostructures, which can be divided into methods for obtaining free structures (for example, the "vapor - liquid - crystal" growth mechanism) and using the methods of planar technology, as well as some others.

  • Growth mechanism "vapor - liquid - crystal"

The most common growth mechanismsemiconductor NWs is a vapor-liquid-crystal mechanism that was demonstrated back in 1964. This method implements the epitaxial growth of NWs by chemical vapor deposition or molecular beam epitaxy.

For this, a thin film of gold is first deposited on the surface of the substrate, which plays the role of a catalyst, after which the temperature rises in the chamber, and the gold forms an array of drops.

Further components for growth are fedsemiconductor material, such as the elements In and P for the growth of InP NWs. The effect of activation by catalyst particles is that growth on the surface under the drop occurs many times faster than on the non-activated surface, thus, the catalyst drop rises above the surface, growing a whisker underneath.

  • Planar technology methods

Sometimes to create one-dimensional nanoobjects,which are also called NWC or nanowires, use planar technology techniques. For example, photolithography and etching methods create vertical grooves or V-grooves on a surface, into which material is deposited. Gathering in these grooves or grooves, the material forms, as it were, one-dimensional nanostructures in the vertical or horizontal directions, respectively.

Another method for obtaining one-dimensional nanostructuresconsists in the fact that a mask layer with a pattern of the desired NWC is created on the SOI-substrate by photo- and electron lithography methods. Then, through this layer, the surface layer of silicon is etched away, leaving only silicon nanowires on the insulator. In some cases, the insulator is also etched out from under the NW, leaving free nanostructures.

  • Spontaneous growth

The easiest method for producing NWC oxidemetal is the usual heating of metals in air can be easily done at home. Growth mechanisms have been known since the 1950s. Spontaneous formation of NWs occurs with the help of crystal lattice defects: dislocations present in certain directions or anisotropy of growth of various crystal faces.

After advancing in microscopy, NW growth has been demonstrated using screw dislocations or twin boundaries.

Khaidukov developed a methodological platformfor reproducible synthesis of nanocrystals, which, being irradiated with low-energy electromagnetic waves, re-emit higher-energy photons after a series of electronic transitions in atoms. Moreover, the spectrum of such radiation can be tuned.

  • Opening

One of the prizes was awarded to the headlaboratory of the Federal Research Center "Crystallography and Photonics" of the Russian Academy of Sciences to Evgeny Khaidukova for the development of advanced technologies on the platform of anti-Stokes nanocrystals.

The nanocrystals synthesized in this way haveapplication prospects in a number of areas. For example, for probing biological processes in cells and practical application in medical diagnostics and therapy. In particular, the development served as the basis for a new method of photodynamic therapy of melanoma using vitamin B2.

Special proteins of plants

One of the prizes was awarded to a team of St. Petersburg scientists for the discovery of amyloid proteins in plants, which are responsible for the accumulation of nutrients inside seeds.

  • Amyloid

Architecturally, amyloid is a non-branching proteinfibrils, consisting of monomers, connected mainly due to hydrogen bonds between β-chains of intermolecular β-layers, located perpendicular to the lateral axis of the fibril.

This variant of the fibril structure is called"Cross-β" and it is the most versatile. β-layers in the amyloid fibril can be located parallel to each other and in the register (similar amino acids of adjacent β-chains are one above the other and are connected by hydrogen bonds).

Amyloids with antiparallelorientation of β-chains. Fibrils of prion (infectious amyloid protein) HET-s ascomycete Podospora anserina in the form of β-helices also have an interesting folding option.

  • Structure

Amyloid has a complex structure.Its main components are proteins, among which both fibrillar (tissue) proteins such as collagen and plasma proteins - α- and γ-globulins, fibrinogen - are found.

Amyloid polysaccharides are presentedchondroitinsulfuric and hyaluronic acids, heparin, neuraminic acid, with chondroitin sulfates prevailing. Amyloid has antigenic properties; resistant to the action of many enzymes, acids, alkalis due to the strength of bonds between protein and polysaccharide components.

  • Opening

For the first time in the world, laureates have discovered in plants andsymbiotic bacteria are specific functional proteins - amyloids, which have a unique resistance to the action of digestive enzymes and can survive for years in the external environment. They were previously found in bacteria, archaea, animals and fungi, but were first found in plants.

A special fibrillar form of proteins - amyloids -became known for its association with a number of diseases caused by abnormal protein aggregation (amyloidosis). In total, there are more than 40 human diseases associated with amyloids, and they are very difficult to treat or are completely incurable (diabetes, cancer, Alzheimer's, and so on).

The discovery of amyloid proteins in plants became possible thanks to the bioinformatics algorithm developed by the authors, which is the most efficient in comparison with analogues.

With its help, for the first time in the world, the entirea set of proteins and it was determined with high accuracy that storage proteins of plant seeds, which are the most important component of the human diet, have a tendency to form amyloids. As well as proteins of symbiotic bacteria, which are responsible for their interactions with plants.

Malignant tumors

Evgenia Dolgov, Ekaterina Potter and AnastasiaProskurina from the Federal Research Center "Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences" was awarded the prize "for the formation of a new ideology in the treatment of patients with malignant tumors based on the time-coordinated action of innovative nucleic acid preparations and cross-linking cytostatics."

The laureates have created and tested two unique technologies for the treatment of tumors of various etiologies, based on previously unknown principles.

  • Panagen

The first technology is the use of the Panagen drug, coordinated with chemotherapy, based on fragmented double-stranded DNA.

Scientists have successfully conducted preclinicalstudies, I and II phases of clinical trials "Panagena" in the treatment of breast cancer. They proved that the drug not only reduces the negative effects of chemotherapy, but also promotes the activation of antitumor immunity.

  • Karanahan

The second technology - "Karanakhan" - is a unique method of selecting the injection regimen of a cytostatic agent that blocks cell division and a drug based on DNA individually for each tumor.

As a result of the joint action of two activesubstances, the destruction of tumor cells, including tumor stem cells, occurs. The technology was successfully tested on experimental mouse and human tumors.

It can be both an independent treatment option and a kind of platform for more effective use of any anticancer drugs and technologies.

Brain-computer interface

Vladimir Maksimenko from "University Innopolis"(Tatarstan) the award was given for the development of invasive and non-invasive brain-computer interfaces for monitoring normal and pathological brain activity.

  • NKI

Neurocomputer Interface (NCI) (also called direct neural interface, brain interface, brain-computer interface) Is a system created for the exchange of information between the brain and an electronic device (for example, a computer).

In unidirectional interfaces, external devicescan either receive signals from the brain or send signals to it (for example, mimicking the retina of the eye when restoring vision with an electronic implant).

Bi-directional interfaces allow the brain andexternal devices exchange information in both directions. The biofeedback method is often used at the heart of the neurocomputer interface.

  • Animal Experiments

Several laboratories managed to record signalsfrom the cerebral cortex of monkeys and rats to control the NCI during movement. The monkeys controlled the cursor on the computer screen and gave instructions to perform the simplest actions to robots imitating a hand, mentally and without any movements. Other studies involving cats have looked at deciphering visual cues.

  • Opening

As a result, the scientist developed a number of mathematicalmodels of neural networks, as well as three neurocomputer interfaces ("brain - computer"). The created interfaces make it possible to prevent and block seizures in patients with epilepsy invasively, that is, by means of electrical stimulation.

For example, this method can be used when medication to relieve an attack is ineffective.

In addition, the interfaces allow non-invasively, thenthere is no penetration through the external integuments of the body, to simulate imaginary motor activity and to determine the concentration of attention, which is important for the rehabilitation of patients after a stroke, when teaching schoolchildren, and so on.

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