If left untreated, bacteria on teeth or damaged skin can surround themselves with a sticky scaffold, forming a biofilm. These bacteria cause great damage to tissues and are difficult to get rid of because mucus protects tissues from antibiotic drugs. A new approach could provide an easy means of removing dirt and eliminating bacteria.
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Scientists at Stanford University and the University of Pennsylvania have created sugar-coated gold nanoparticles used to image and destroy biofilms. Scientists have shown how nanoparticles can be used for diagnostic and therapeutic purposes on teeth and damaged skin in rats and mice. This study Journal of Clinical Investigation,
They were able to remove biofilms within 60 seconds and in this respect outperformed existing antibacterial agents.
This platform allows the destruction of biofilms without the need for surgical removal of the infection, which may be necessary when using antibiotics. In addition, this method can treat patients who are allergic to antibiotics or infected with drug-resistant strains, and the great advantage is that it is antibiotic-free..
Dr. Luisa Russell, Program Director, Discovery Science and Technology, NIBIB.
bacterial strep throat mutans It can form oral biofilm or plaque, which can lead to serious cavities. Common causes of wound infection, staphylococcus aureus bacteriaThe healing process may be significantly delayed.
Regardless of the situation, the tightly woven web of proteins and carbohydrates found in biofilms can prevent antibiotics from reaching all bacteria in the infected area.
But that's not the only problem biofilms cause. Not only are they difficult to remove, but they are also difficult to identify in the first place.
This new study finds that gold may be the answer to solving both problems simultaneously.
Because gold is non-toxic and easily converts the energy of a light source into heat, it is an excellent choice for photothermal therapy, a tactic that uses the heat of nearby pathogens to kill them. In addition to producing heat, gold particles react to light by emitting detectable ultrasound waves, so they can be viewed using a method called photoacoustic imaging.
The authors of the new study optimized the gold spheres' response to light for both therapeutic and imaging applications by enclosing them within larger golden cage-shaped nanoparticles. They covered the particles with dextran, a common carbohydrate used to form biofilms, making them attractive to bacteria.
If you place gold nanoparticles on it, S. mutans-By harvesting infected teeth from rat jaws in vitro, the researchers evaluated their approach.
During photoacoustic imaging tests on teeth, the researchers were able to pinpoint where the biofilm had absorbed the dextran-coated particles on the teeth, thanks to the clear and loud signal from the nanoparticles.
They then used a laser to irradiate the teeth to evaluate the particles' therapeutic effectiveness. They applied the topical antiseptic chlorhexidine to samples of other infected teeth as a point of comparison.
Researchers found a clear difference between the results of the two treatments. Photothermal therapy almost completely killed the biofilm, whereas chlorhexidine had no noticeable effect on bacterial viability.
Especially in the case of oral infections, treatment is quick. We turn the laser on for a minute and it actually kills basically all the bacteria in about 30 seconds..
Dr. Maryam Hajfathalian, Professor of Biomedical Engineering at New Jersey Institute of Technology and first author of the study
Maryam Hajfathalian conducted this research as a postdoctoral researcher at the University of Pennsylvania and Stanford University.
test target staphylococcus aureus aureusInfected mice with open skin wounds were also successful because the heat generated by the nanoparticles far exceeded the effectiveness of gentamicin, another antibacterial agent.
Here the temperature increased by 20°C and was restricted to the biofilm. The researchers' measurements showed that there was no harm to surrounding tissue.
The authors say they hope to demonstrate through further testing whether this method can prevent cavities or promote healing.
I think it's important to look at how cheap, simple, and fast this process is. Because antibiotic use is limited, new treatments are needed to replace them..
Dr. Maryam Hajfathalian, Professor of Biomedical Engineering at New Jersey Institute of Technology and first author of the study
Journal references:
Hajpatalian, M.; except (2023) Theranostic gold-in-gold caged nanoparticles enable photothermal ablation and photoacoustic imaging in a biofilm-associated infection model. Journal of Clinical Investigation. doi.org/10.1172/JCI168485
Source: https://www.nih.gov/