Antibacterial bioactive glass doubles down on microbial resistance to antibiotics

Date:
February 24, 2022
Source:
Aston University
Summary:
Infections linked to medical devices such as catheters, dental
implants, orthopaedics and wound dressings could be dramatically
reduced using a simple technique, according to new research.



FULL STORY ========================================================================== Infections linked to medical devices such as catheters, dental implants, orthopaedics and wound dressings could be dramatically reduced using a
simple technique, according to new research.


========================================================================== Scientists at Aston University have found a way to significantly increase
the antimicrobial properties of a material used in many medical devices
and clinical surfaces: bioactive glass.

The Aston University team had already developed bacteria-killing
bioactive glass laced with a single metal oxide of either zinc, cobalt
or copper. Their latest research combined pairs of metal oxides in the
material -- and found that some combinations were more than 100 times
better at killing bacteria than using single oxides alone.

Bioactive glass is made from high-purity chemicals designed to induce
specific biological activity, but the type currently in clinical use --
often as a bone filler -- does not contain antimicrobial substances. The
Aston University research showed that combinations of metal oxides
can improve the antimicrobial properties of bioactive glass and the
researchers believe this approach could be applied to other materials
for clinical use.

Many bacteria that cause infections -- such as Escherichia coli
and Staphylococcus aureus -- are becoming increasingly resistant to antibiotics, so new ways to prevent infections are urgently needed.

Professor Richard Martin, who led the research at Aston University's Engineering for Health Research Group, said: "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." Professor Martin and his
colleagues Drs Tony Worthington and Farah Raja created bioactive glass
laced with small amounts of cobalt, copper or zinc, and combinations
of two of the three oxides. They then ground these into a powder which
they sterilised, before adding it to colonies of E. coli, S. aureus and
a fungus, Candida abicans. They compared the effects of the standard
glass and glass with either solo metal oxides or the combinations,
measuring bacterial and fungal kill rates over 24 hours.

All of the metal oxide-laced glass -- both single and combined --
performed better than the glass alone. Copper, combined with either
cobalt or zinc, had the strongest effect on the bacteria, followed by
a combination of cobalt and zinc. Both copper combinations were over
one hundred times better than single oxides at killing E. coli, while
copper and zinc was similarly effective against S. aureus. The cobalt
and zinc combination had the strongest effect on the fungus.

Professor Martin said: "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."
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 colonisation 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." ========================================================================== Story Source: Materials provided by Aston_University. Note: Content may
be edited for style and length.


========================================================================== Journal Reference:
1. Farah N. S. Raja, Tony Worthington, Lucas P. L. de Souza, Shirin B.

Hanaei, Richard A. Martin. Synergistic Antimicrobial Metal
Oxide-Doped Phosphate Glasses; a Potential Strategy to Reduce
Antimicrobial Resistance and Host Cell Toxicity. ACS Biomaterials
Science & Engineering, 2022; DOI: 10.1021/acsbiomaterials.1c00876 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220224125204.htm

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