Nanotechnologies make humans beings contact with nanoparticles. But are they safe for human health? This is what Russian pharmacologists think.

What is a nanoparticle? Nanoparticles are very small artificial items, which never exceed 100 nanometers (one billion of nanometers are equal to one meter) in diameter. Nanoparticles can have various nature: liposomes (lipid vesicles), emulsions, polymer, ceramic, carbon and metal particles. These tiny particles have numerous applications – for instance, they can be used in medicine, anti-wrinkle creams and sun-protection cosmetics. Nanoparticles are able to permeate into epithelial cells, propagate in processes of neurons, blood and lymphatic vessels. Another wonderful ability is that they can selectively accumulate in cells of various types and specific cell structures. This surprisingly high penetration power makes nanoparticles priceless medical components, as well as increases their potential as health harming agents. Nevertheless, not much is known about how nanoparticles affect frail human organisms.

Russian scientists suggest establishing new discipline, “nanotoxicology”, which deals with very important matters – studying fundamental patterns for development of biological effects and toxicity of nanoparticles depending on their shape, size, parent materials, surface area, charge and other physical and chemical structure features. This new scientific field will also cover issues of doses, administration way, concentration near target organs and time of exposure. Biologists emphasize the importance of correct predictions of possible delayed actions of nanotherapy.

Since toxicity of medical substances and nanoparticles, based on said substances, may be totally different, medics cannot use common preclinical drug safety evaluation methods for nanoparticles. Here is an example – properties of nanoparticles should be studied on living organisms, rather than on cell cultures. Russian pharmacologists managed to find undesirable genetic effects of zeolite particles only using specially designed technique. Since medical nanoparticles are designed for human nanotherapy, they should be tested on laboratory animals, simulating certain diseases. Moreover, we should not forget about genetic heterogeneity of human population, that is why large number of people could show extremely high sensitivity to nanoparticles.

Development of adequate evaluation technique for toxic effects of nanoparticles and performance of necessary experiments require significant amount of time, which will postpone triumphant introduction on nanotherapy into modern medicine. Nanotechnologies shouldn’t outrun toxicological evaluation of nanoparticles; however, this negative tendency appears to predominate in our society. Leaving apart ethical aspects and unpredictable medical consequences, introduction of potentially unsafe products may cause enormous financial losses. Development of a new drug requires about $800 million, and all this heap of money would be lost, if the drug turns out to be toxic.

Source:
    Science News

Kizilova Anna