Page 28 - Plastcs News August 2017

FEATurES
FEATurES

Hacking plastics with silver and electricity

Researchers have developed an innovative way of hacking conducting plastics so as to prevent
bacterial growth using silver nanoparticles and a small electrical current. The method could prove
to be useful in preventing bacterial infections in hospitals.

ospital wards are full of patients and many applying tiny electrical currents to a conducting plastic
Hdevices, each one potentially harbouring dangerous surface had no effect on bacterial growth. on a similar
microbes. Bacteria are capable of surviving for a long surface exposing an attached layer of silver nanoparticles,
time on plastic surfaces, from which they can spread to bacterial growth was reduced. However, application of a
patients and cause infections. tiny electrical current to the latter surface enhanced the
effect of attached silver nanoparticles, and the bacteria
While both large electrical currents and high silver
were completely destroyed.
concentrations are known to kill bacteria, they also pose
a risk to humans, which is why their use in hospitals “It’s a phenomenon known as the bioelectric effect,
is limited. New research lead by Professor Agneta whereby electrical fields weaken bacterial cells against
Richter-Dahlfors at Karolinska Institutet’s Department external attacks”, says PhD student Salvador Gomez-
of Neuroscience shows that it is not necessary to use Carretero at Karolinska Institutet's Department of
dangerous concentrations of silver or large currents in Neuroscience. “We use electrical signals to increase the
order to kill bacteria, if these are used in combination. antimicrobial activity of the silver nanoparticles. This
reduces the amount of silver needed, which is beneficial
“By targeting the bacteria on several fronts at the same
for both the patient and the environment.” In the future,
time, the effect of different small attacks becomes larger
than when each factor is acting on its own”, explains the researchers hope that this technology will help to
keep surfaces in hospitals and other settings requiring
Agneta Richter-Dahlfors.
high hygienic standards free from bacteria that can cause
The research team focussed on the notorious hospital life-threatening infections.
pathogen Staphylococcus aureus. They found that
“It has not yet been tested in the clinic, but we believe
this technology could
be a good approach to
limiting the spread of
infectious bacteria and
the incidence Richter-
Dahlfors of hospital-
acquired infections”
says Professor Richter-
Dahlfors. The study was
financed by the Swedish
Re se a rch Cou n cil,
Vinnova, Carl Bennet
AB and the Swedish
Medical Nanoscience
Center.

Plastics News | August 2017 28