According to a new study, infections linked to medical devices like dental implants, catheters, orthopedics and wound dressings could be considerably reduced with the help of a simple method.
Image Credit: Aston University.
At Aston University, researchers have discovered a method to considerably increase the antimicrobial properties of a material utilized in several medical devices and clinical surfaces: bioactive glass.
The Aston University team came up with a bacteria-killing bioactive glass laced with a single metal oxide of either zinc, copper, or cobalt. Their new study combined pairs of metal oxides in the material and discovered that a few combinations were more than 100 times better at killing bacteria compared to using single oxides alone.
Bioactive glass is created from high-purity chemicals developed to induce particular biological activity, but the type existing in clinical use — often as a bone filler — does not consist of antimicrobial substances. The Aston University study showed that combinations of metal oxides can enhance the antimicrobial properties of bioactive glass, and the scientists believe this approach can be employed to other materials for clinical use.
Several bacteria that cause infections like Staphylococcus aureus and Escherichia coli are turning out to be increasingly resistant to antibiotics. Hence, new approaches to avoid infections are required immediately.
Antibiotic drugs have been used in combination since the 1950s, as two antimicrobials can broaden the spectrum of coverage by aiming for different bacterial targets at the same time. Our research is the first to show that this combination approach can work with materials as well.
Richard Martin, Study Lead Author and Professor, Engineering for Health Research Group, Aston University
Professor Martin and his collaborators Dr. Tony Worthington and Dr. Farah Raja made bioactive glass laced with small amounts of cobalt, zinc or copper, and combinations of two of the three oxides.
Furthermore, they ground these into a powder which was sterilized, before adding it to colonies of E. coli, S. aureus and a fungus, Candida albicans. They made a comparison of the effects of the standard glass and glass with either solo metal oxides or the combinations, thereby quantifying fungal and bacterial kill rates over 24 hours.
All of the metal oxide-laced glass, including both single and combined, did perform better compared to the glass alone. Copper, integrated with either cobalt or zinc, exhibited the strongest effect on the bacteria, tracked by a combination of zinc and cobalt.
Both copper combinations were over one hundred times better compared to single oxides at killing E. coli, while copper and zinc turned out to be similarly effective against S. aureus. The cobalt and zinc combination possessed the most powerful effect on the fungus.
It was exciting to run our experiments and find something that is significantly better at stopping infection in its tracks and could potentially reduce the number of antibiotic treatments that are prescribed. We believe combining antimicrobial metal oxides has significant potential for numerous applications including implant materials, hospital surfaces and wound healing dressings.
Richard Martin, Study Lead Author and Professor, Engineering for Health Research Group, Aston University
Dr. Worthington added, “We have shown that co-doping surfaces with these combined antimicrobial metals, including copper, zinc, and cobalt, could reduce bacterial adhesion and colonization to surfaces or devices used in clinical practice.”
“The use of antimicrobial metals is potentially the way forward, given discovery of new antibiotics is currently limited. We would urge manufacturers to investigate whether our new approach could be used for their biomedical materials,” concluded Dr Worthington.
Journal Reference:
Raja, F. N. S., et al. (2022) Synergistic Antimicrobial Metal Oxide-Doped Phosphate Glasses; a Potential Strategy to Reduce Antimicrobial Resistance and Host Cell Toxicity. ACS Biomaterials. doi.org/10.1021/acsbiomaterials.1c00876.
Source: https://www.aston.ac.uk/