Thursday , August 5 2021

Scientists have developed a new method for producing irradiated nanomaterials for medical applications



A number of researchers, both under the leadership of the Petr Cígler Institute for Organic Chemistry and Biochemistry (IOCB Prague) and Martin Hrubý of the Institute for Macromolecular Chemistry (IMC), both of which were part of the Czech Academy of Sciences. A revolutionary method for the easy and inexpensive production of irradiated nanodiamonds and other nanomaterials suitable for use in high-precision diagnostics of diseases, including various types of cancers. His articles have recently been published in scientific journals Nature Communication.

Diagnosing diseases and understanding the processes within the cell at the molecular level requires sensitive and selective diagnostic tools. Nowadays, scientists can observe the magnetic and electric fields in the cells with a few dozen nanometers resolution and crystal defects in the particles of certain inorganic substances. An almost ideal material for these purposes is diamond. Compared to diamonds used in jewelry, those designed for diagnostics and nanotube – nanodiamonds applications are approximately one million times smaller and are synthetically produced from graphite at high pressures and temperatures.

However, a pure nanodiamond does not reveal much about its surroundings. First, the crystal lattice must be damaged under controlled conditions to create special defects called nitrogen-evacuation centers that provide optical imaging. Damage is most commonly generated by irradiating nanodiads with rapid ions in particle accelerators. These accelerated ions detach carbon atoms from a nanodiamond crystal lattice and match nitrogen atoms in the crystal as pollutants at elevated temperatures, leaving holes known as voids. The newly formed nitrogen-evacuation centers are a source of fluorescence which can then be observed. Exactly this gives great potential to nanodiamonds for fluorescent drugs and technology applications.

However, a major limitation to the use of these materials on a larger scale is the low cost and low efficiency of ions irradiated with an accelerator; this prevents the production of larger amounts of this valuable material.

The team of scientists from various research centers, chaired by Petr Cígler and Martin Hrubý, recently published an article in the magazine. Nature Communication Explains a completely new method of irradiating nanocrystals. Instead of costly and time-consuming irradiation in an accelerator, scientists have used radiation in the nuclear reactor much faster and much cheaper.

But it wasn't that simple. Scientists had to use a trick – in the reactor, the neutron radiation divides boron atoms into very light and fast ions of helium and lithium. The nanocrystals must first be dispersed into molten boron oxide and then exposed to neutron rays in a nuclear reactor. Neutron capture by boron nuclei produces a dense helium and lithium ions shower which has the same effect on nanocrystals as ions produced in an accelerator: controlled generation of crystal defects. The use of a reactor to irradiate a much larger amount of material from the high density of this particulate shower and the use of a reactor is easier and more cost effective to produce a gram of random random nanomaterials at once, which is about one thousand times more than scientists. Thus, they were obtained by comparable irradiation in accelerators.

The method has been successful in creating defects in silicon carbide not only in the nanodiamonds cage, but also in another nanomaterial. Scientists therefore assume that the method can find universal application in the production of large-scale nanoparticles with defined defects.

The novel method uses the principle of boron neutron capture therapy (BNCT), in which patients are administered a boron compound. After the compound is collected in the tumor, the patient receives radiation therapy with neutrons dividing boron nuclei into helium and lithium ions. These then destroy the tumor cells collected by the pipe. This principle, taken from this experimental cancer treatment, has opened the door to the efficient production of nanomaterials with extraordinary potential for applications that have been diagnosed with cancer as well as other fields.


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