Scientists May Have Found a Way to Kill Antibiotic-Resistant Bacteria with Oxygen and Light

Monday, 20 August 2018 - 11:55AM
Medical Tech
Monday, 20 August 2018 - 11:55AM
Scientists May Have Found a Way to Kill Antibiotic-Resistant Bacteria with Oxygen and Light
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Image Credit: Pixabay Composite

For years, the infectious disease staphylococcus aureus weathered everything the medical community could throw at it, being whittled down by antibiotics until only the hardiest strains were left. This created a new type of disease, called MRSA (methicillin-resistant staphylococcus aureus), which has since become the bane of hospitals worldwide. Because hospitals can't rely on antibiotics to clear out MRSA from their facilities, hospitals have ironically become one of the chief hotbeds for MRSA infections. Now, however, medical scientists have found a new way to fight MRSA using two unlikely tools: light and oxygen.

Dr. Peng Zhang, one of the leaders of the new study, described the new technique's mechanism of action:

Opening quote
Instead of resorting to antibiotics, which no longer work against some bacteria like MRSA, we use photosensitizers, mostly dye molecules, that become excited when illuminated with light. Then, the photosensitizers convert oxygen into reactive oxygen species that attack the bacteria.
Closing quote


For clarification, "oxygen species" are types of molecules that contain oxygen and react with other molecules in cells. They've been proposed before as a potential treatment for infections, but there were two major drawbacks: first, the oxygen molecules couldn't be focused in one area long enough to do significant damage to a disease. As Zhang explains it: "If you want to attack a castle, and you just let all these people attack individually, it is not very effective. Instead, if you have the same number of people grouped together attacking the castle at one point, it is possible to cause more damage." Second, the molecules were hydrophobic – water-repelling – meaning that they couldn't be used in water-based mediums, where a lot of bacteria and other microorganisms live.

By lacing the photosensitizers with "noble metal nanoparticles decorated with amphiphilic polymers," Zhang's team was able to create a new blend that could overcome these drawbacks and do major damage to a range of diseases, including MRSA, which is still weak to this method of treatment. Going forward, these new photosensitizers may even be used to treat skin cancer.


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