Re-Blogged From The Silver Institute
By coating silver-silica nanoparticles with an antibiotic,
Brazilian scientists have found a more powerful way to kill
Normally, silica compounds – silica is the mineral quartz
– are toxic when inhaled, causing the disease silicosis in
which the particles scar the lungs making it difficult to
breathe. Silicosis often is seen in foundry workers, glass
makers and those who work in rock quarries.
However, when the research team wrapped the antibiotic
ampicillin around silver-silica it renders it harmless allowing
both the silver ions and antibiotic to kill germs without
harming human cells.
The combination has not been tested on people, but
laboratory results show that it overcame a strain of
E. coli that was resistant to antibiotic drugs alone.
“There are commercial drugs that contain nanoparticles,
which typically serve to coat the active ingredient and
extend its lifetime inside the organism.
Our strategy is different. We decorate the surface of the nanoparticles with
certain chemical groups that direct them to the site where
they’re designed to act, so they’re highly selective,” said
Mateus Borba Cardoso, lead study author and a researcher
at Brazil’s National Energy & Materials Research Center
(CNPEM) in an interview in Phys.org.
“We used molecular modeling to find out which part of
the ampicillin molecule interacted most with the bacterial
membrane,” he added. “We then arranged all the molecules
of the drug so that this key part was facing outward from the
nanoparticle, increasing the likelihood of interaction with
The silver-silica/antibiotic treatment has a drawback. Silver-
silica is inorganic and humans don’t metalize it, so it could
build up in the body. Cardoso said that his group is studying
this issue to learn whether it presents a danger or not. He
plans to do animal testing.
One possibility is to developa nanoparticle that can be excreted through urine. He
suggests, though, that for patients for whom no other cure
exists for their bacterial infection, the silver-silica/antibiotic
mixture offers hope where none is available.