Malignant neoplasms received their epithet for the rapid invasive growth and the release of toxic substances. They very quickly metabolize and "steal" oxygen from nearing tissues. However, they themselves can also have hypoxic areas - due to the rapid absorption of oxygen. Created nanosystems of targeted drug delivery — liposomes, micelles, and polymeric nanoparticles — are transported by the bloodstream, but some places cannot create a sufficient concentration of the drug.
Employees of the McGill and Montreal Universities decided to use the strain of Magnetococcus marinus (MC-1) for chemotherapy. Its organelles, magnetosomes, crystals of magnetic iron oxide in the lipid membrane are sensitive to a magnetic field. In addition, the microorganism is sensitive to the concentration of oxygen and moves along this vector. MC-1 moves along the Earth’s magnetic field lines to zones with low oxygen content. Modified diatoms seaweeds behave similarly to Magneticococcus, and their study is conducted in parallel.
In the experiment, Magnetococcus marinus were introduced to immunodeficient mice with colon carcinoma. After that, the tumor area was affected by a magnetic field and the concentration of bacteria was studied. Magnetococci were ignored by systems of biological protection and precisely accumulated in hypoxic sites, unlike polymer nanospheres.
Then covalently bound liposomes were implanted on MS-1 with SN-38, the active metabolite of iridotecan. Liposomes were accumulated in areas of hypoxia and necrosis after the introduction of bacteria into the tumor but the release of cytokines - the immune response of systems of biological defense to bacteria - did not occur. This technique has a minimal toxic effect on the body. Moreover, the introduction of more than 100 million bacteria did not cause the release of cytokines (evidence of an inflammatory reaction) and did not harm the blood cells of animals. The technique deliberately delivers drugs to hard-to-reach areas of tumors more effectively than artificial nanosystems, reducing the toxic effects on other organs. Moreover, its experimental use in animals had no pronounced side effects.
According to researchers, in the future, the effectiveness of the MS-1 can be further improved by genetic modification of bacteria and improving the algorithms of their magnetic guidance.
As already mentioned, liposomes, micelles, polymeric microspheres, and other nanoconstructions and biological defense systems are used for targeted drug delivery. All of them have disadvantages that limit their use. Various scientific teams around the world are constantly engaged in their improvement: nano-micelles were taught to penetrate the brain in Berkeley, in Barcelona there are transport "magnetic carpets", and scientists in the USA disguised polymeric nanoparticles from biological membrane protection systems of platelets.
Oncology is the scourge of present times, but the spread of natural infections, as well as natural disasters and accidents at hazardous industries, leading to leakage of pathogens, toxins and other toxic substances, are no less dangerous for society. In addition, the threat of deliberate spraying of biological hazards remains fairly high, therefore adequate safety measures are of great importance. WestMedGroup offers biological protection systems for emergency services: portable stretcher insulators and other.
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