Nanomesh has a golden touch for killing bacteria
By precisely targeting the delivery of antibiotics to where they're needed most, smaller amounts of them need to be administered. This means fewer side effects, along with a reduced likelihood of bacteria developing a resistance to the drugs. With these facts in mind, a new gold-doped nanomesh has been designed as an alternative to pills or needles.
The material, which was created via a collaboration between scientists at Australia's Flinders University and Japan's National Institute for Materials Science, is intended to be applied or implanted at infection sites. It's made of a biocompatible, biodegradable polymer known as polycaprolactone, to which antibiotics and electrically-charged gold nanoparticles are added while it's still in a liquid state.
The actual mesh is formed via an electrospinning process, in which the liquid polymer is extruded from a syringe through a needle, passing through a high-voltage electrical field before forming into tiny fibers on an aluminum foil substrate. That collection of fibers is then peeled off the foil, and dried in a vacuum.
In lab tests, discs of the mesh were placed in petri dishes containing populations of harmful E. coli bacteria. Over a 14-day period, the antibiotics were gradually released from the mesh as it degraded, killing the microbes.
In cases where the gold nanoparticles were positively charged, they helped by damaging bacterial membranes. That said, it was found that negatively-charged nanoparticles caused certain antibiotics to migrate toward the center of the fibers, thus prolonging the release period. Either way, the material shows promise.
"Although the dosage is reduced compared to an oral dosage, the concentration of antibiotics delivered to the infection site can still be higher, ensuring the bacteria cannot survive which will reduce instances of resistance," says Flinders' Assoc. Prof. Ingo Koeper. "This research, as a proof of concept, suggests an opportunity for fabricating nanomeshes which contain gold nanoparticles as a drug treatment."
A paper on the study was recently published in the journal RSC Advances.