Nanomedicine: How Radiation Medicines Work

Nanomedicine: How Radiation Medicines Work
Nanomedicine: How Radiation Medicines Work

The danger of radiation lies in the high penetrating ability of very small particles of high energies into living tissues, so scientists are fighting its consequences with "nanoweapons".

Not only rare major accidents at nuclear power plants and the consequences of testing nuclear materials can be sources of radiation, destructive to all living things. Radioactive clouds, cosmic radiation that penetrates the Earth through ozone holes in the atmosphere protecting from it, radiation in space during long-distance interstellar flights, and finally, radiation therapy for cancer patients - all this is a potential threat to health.

What exactly does radiation harm? The degree of destruction of living tissues depends on the energy and type of radiation. There are two negative scenarios worth highlighting. DNA can be directly exposed to radiation. In this case, mutations occur that can distort the life of both the irradiated person and his offspring.

Another scenario is the destruction of water molecules in living organisms, leading to the formation of free radicals called reactive oxygen species (ROS). Radicals damage cells and tissues, causing sepsis, cancer, cardiovascular disease, and Parkinson's disease.

The second scenario is the most dangerous: while the radiation particles "get" to the DNA, they will lose energy in the tissues of the body, simultaneously destroying them. Fortunately, this process can be controlled to some extent by antioxidant nanomaterials. Cerium oxide (CeO2) and manganese oxide (Mn3O4) nanoparticles help to bind and remove ROS from the body. The minus of the medicine is in large doses required for a noticeable effect.

Scientists are constantly improving anti-radiation means. So, researchers from the Institute of Basic Sciences in South Korea played with nanoparticles of the mentioned oxides and found that if they are "stacked on top of each other", the required dose of the drug is reduced many times. Due to the connection with manganese oxide, an additional vacancy appears on the surface of cerium oxide, which is in a hurry to occupy too active oxygen generated by the rampage of radiation in the body.

Nanoparticulate drugs are being tested on human organelles - small copies of organs grown from stem cells - and laboratory animals. A Korean radiation pill, for example, has been tested on a model "intestine" and has shown good results. Organoids pretreated with nanocrystals of manganese and cerium oxides expressed more genes associated with maintaining intestinal stem cells, and fewer genes responsible for their death.

Experiments on mice have shown that a small enough dose is enough for 67% of the animals to survive after 30 days of exposure to radiation. In the bodies of mice that received the nano-drug, there were fewer oxidative processes and fewer disturbances in the circulatory system and bone marrow cells were noticed. The dose of the Korean drug was 360 times lower than the standard "portion" of amifostine, which is "fed" to patients with radiation therapy.

At the moment, a medicine made from nanocrystals of cerium and manganese oxides is not yet ready for human use. However, its very appearance in the scientific arena suggests that researchers have made great strides in understanding the effect of radiation on living organisms and will soon enhance the effectiveness of existing drugs.