A plastic bottle recycling product will help fight infections



    Scientists from IBM Research, together with the Singapore Institute of Bioengineering and Nanotechnology, synthesized a polymer based on polyethylene terephthalate, deadly for fungal infections and at the same time low toxicity for mammalian cells. Polyethylene terephthalate (PET) is a cheap and common material that ordinary plastic bottles are made of.

    Unlike most antibiotics and antifungal drugs, the polymer does not penetrate the fungal cell, disrupting its metabolism, but destroys its cell membrane. Thanks to this, it is impossible to develop infections that are resistant to the drug - if pathogenic bacteria and fungi can adapt to almost any poison, forming new forms resistant to antibiotics, then the new drug literally breaks the cells into pieces. Moreover, it acts quite selectively, almost without affecting the cells of the body.

    During laboratory tests, the fungal colony was brought to almost complete destruction 11 times in a row, treated with a reduced dose of the drug, and then allowed to recover - no signs of the development of drug resistance were detected. At the same time, a common antifungal drugfluconazole already after 6 such repetitions lost effectiveness.

    The fact that the new drug is a polymer, that is, a long chain of atoms consisting of repeating fragments, is of great importance for its effectiveness - the agents that destroy the cell membrane do not act alone, but together, their local concentration is very high at the point of contact of the polymer chain with the membrane , despite the fact that the average concentration of the substance in the solution is quite small.

    To test the effectiveness and safety of a new antifungal agent, a series of experiments on rats was carried out. Rats were infected with Candida albicans- one of the common types of fungus, which often causes nosocomial infections, is resistant to many antifungal drugs and can cause serious complications after diseases or medical procedures associated with a decrease or suppression of natural immunity. In rats, fungal keratitis was induced, an infection of the cornea that often occurs when contact lenses are worn.

    Tests have shown the high efficiency of the new polymer even for drug-resistant forms of the fungus, while the corneal cells remained almost untouched. Blood cells also reacted poorly to the drug, although their destruction is a fairly typical side effect for most drugs that act on the cell membrane.


    Colony of C. albicans before and after treatment. On the right are the remains of destroyed cell membranes. Another polymer antibiotic recently developed by IBM

    works in a similar way . It also destroys the cell membrane and is effective against antibiotic-resistant Staphylococcus aureus. From this infection in the United States alone, about 18,000 people die every year. This variety of bacteria has evolved under the conditions of the “arms race” between antibiotics and bacteria that has been going on since the discovery of penicillin - it is insensitive to almost all known antibacterial drugs.

    Interestingly, the technologies and techniques used in the synthesis of new antimicrobial polymers are based on IBM's experience in the manufacture of microcircuits. Materials capable of effectively destroying the cell membrane were obtained during the work on the technology of etching the substrate of the microcircuit on an atomic scale. IBM Research now has a full-fledged research program in the field of nanomedicine. Scientists believe that such drugs have a future, because the increasing spread of antibiotic-resistant infections is already causing some researchers to draw apocalyptic pictures of a world in which antibiotics no longer work.

    An article on the new antifungal polymer was published in the journal Nature Communications on December 9 this year.


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