Bugging superbugs: Black Phosphorus kills antibiotic resistant bacteria and fungi

To address antibiotic-resistant bacteria “superbugs”, a nanothin coating made of black phosphorus was innovated by Royal Melbourne Institute Technology (RMIT) scientists in Melbourne, Australia.

Bacterial infection became more prevalent especially during the surge of the COVID-19 virus which directly and indirectly affected the body’s immune system. In some cases, patients develop antimicrobial resistance from antibiotic abuse which leads to ineffective antibiotic treatments.

Research on black phosphorus (BP) have featured antibacterial and antifungal properties but are unpopular to clinical settings. In the presence of oxygen, BP is easily degraded which makes it ideal for combatting microbes.

Nanothin layer of black phosphorus (red) disintegrates a fungal cell (green), Photo by Gosia Kaszubska. Source: RMIT University

Oxidation of black phosphorus releases reactive oxygen species (ROS) that can disrupt the bacterial and fungal cell wall. This cell wall serves as the protective layer that envelops an organism’s DNA and cell organelles which allow a bacterium or fungus to exist. Destroying their cell wall, thereby, stops their membrane and cellular processes from functioning which eventually kills them.

To test BP’s defensive properties against bacteria and fungi, five common bacteria strains including E.coli and drug-resistant MRSA and five kinds of fungus were used as samples in the study. In about two hours, 99% of the samples were eliminated indicating high efficiency of BP as an antimicrobial agent.

Additionally, BP completely dissolves in the body within 24 hours. This contributes to its practicality for drug development since altering its composition or coated substrate to disintegrate in the body is proven unnecessary. Its self-degrading properties also implicate only minimal and short-lived side-effects at most.

Despite the reassuring results from the study, the utilization of BP as an antimicrobial agent is still under observation and requires further research as well as clinical trials before it can be manufactured and distributed to the public.

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Sources:

Shaw, Z. L., Kuriakose, S., Cheeseman, S., Mayes, E., Murali, A., Oo, Z. Y., Ahmed, T., Tran, N., Boyce, K., Chapman, J., McConville, C. F., Crawford, R. J., Taylor, P. D., Christofferson, A. J., Truong, V. K., Spencer, M., Elbourne, A., & Walia, S. (2021). Broad-Spectrum Solvent-free Layered Black Phosphorus as a Rapid Action Antimicrobial. ACS applied materials & interfaces, 10.1021/acsami.1c01739. Advance online publication. https://doi.org/10.1021/acsami.1c01739

Roberts, G. (2021). Nanothin Layer on Wound Dressings Kills 99% of Antibiotic-Resistant Bacteria. Science Times. Retrieved 15 April 2021, from https://www.sciencetimes.com/amp/articles/30671/20210414/nanotechnology-antibiotics-wound-dressings.htm.