Undergraduates of Nanjing University of Technology develop oxygen-transmitting nanoemulsions against drug-resistant bacteria

Preparation of nanoemulsion and mechanism of action Photo courtesy of Nanjing University of Technology methods to combat drug-resistant bacteria
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Under the guidance of Miao Wenjun, deputy dean of the School of Pharmacy, Nanjing University of Technology, Niu Peiyuan, Feng Duxiang and Wang Zeyu, three undergraduates from the School of Pharmacy, Nanjing University of Technology, designed and prepared an oxygen-transporting nanoemulsion, which can be used to improve and improve the resistance of antibacterial photodynamic therapy.
Inactivation efficiency of gram-negative bacteria
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Recently, related research results were published in "Pharmaceuticals" under the title "Perfluorocarbon Nanoemulsion Sensitization Photodynamic Inactivation of Resistant Gram-negative Bacteria".
Niu Peiyuan is the first author of the paper, and Miao Wenjun is the correspondent.
author
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"Why we advocate less use of antibiotics is because bacteria are resistant to resistance and new broad-spectrum antibiotics are difficult to develop
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" Miao Wenjun said that once bacteria develop resistance in the human body, it is difficult to have a reliable clinical solution to combat this situation
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According to reports, bacteria are divided into gram-negative bacteria and gram-positive bacteria.
The team found through previous research that gram-positive bacteria are very sensitive to antibacterial photodynamic therapy, the effect is good, and it is not easy to develop drug resistance
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According to Niu Peiyuan, photodynamic therapy has three elements: photosensitizer, oxygen, and light
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The photosensitizer transfers the energy of light to the oxygen molecule, so that the oxygen molecule becomes an active state and deoxidizes the biological macromolecules.
The oxidized biological macromolecules will lose their original functions and will die if they cannot replicate and multiply.

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However, at the same time, the team found that due to the unique cell wall structure of Gram-negative bacteria, the therapeutic effect of antibacterial photodynamic therapy was not satisfactory, and drug-resistant Gram-negative bacteria gradually replaced drug-resistant Gram-positive bacteria as the cause of nosocomial infection.
main pathogenic bacteria
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Feng Duxiang said that the sensitivity of gram-negative bacteria is one-tenth of that of positive bacteria, that is, the dose of the drug must be increased by about ten times to obtain the same effect
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Aiming at the insensitivity of Gram-negative bacteria to antibacterial photodynamic therapy, the team designed and prepared an oxygen delivery nanoemulsion-Ce6@FDC, using perfluorodecalin as oxygen delivery material to supplement the rapidity of photodynamic therapy.
Oxygen consumption improves and enhances the photodynamic inactivation efficiency of drug-resistant Gram-negative bacteria
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According to Wang Zeyu, the oxygen-delivering nanoemulsion is the carrier of the drug, just like the capsules that people usually eat.
The nanoemulsion is equivalent to the shell of the drug, and the photosensitizer inside is the drug.
This shell can enhance the effect of the drug
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Taking Escherichia coli as an example, compared with the traditional free photosensitizer chlorin e6 (Ce6), under the same conditions, in the experiment of photodynamic against planktonic bacteria, the oxygen-delivering nanoemulsion increased the number of bacteria after the photodynamic effect was enhanced.
The average logarithmic unit decreased from 5.
1 to 3.
3; in the biofilm removal experiment, the number of live bacteria in the biofilm decreased by 5.
2 logarithmic units after the oxygen delivery nanoemulsion enhanced photodynamic force, and the resistant Gram-negative bacteria were inactivated.
Efficiency is significantly improved
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Related paper information: https://doi.
org/10.
3390/ph15020156