Researchers from Flinders University, along with collaborators in Japan, have developed a nanomesh capable of delivering drug treatments. It is hoped that effective antibiotic delivery via the nanomesh will be a major step forward in the fight against global antibiotic resistance.

To determine the effectiveness of the nanomesh, two antibiotics used in the treatment of bacterial infections — colistin and vancomycin — were added to the mesh together with gold nanoparticles, and tested over a 14-day period by PhD student Melanie Fuller.

Flinders Institute for Nanoscale Science & Technology Associate Professor Ingo Koeper said 20 x 15 cm pieces of mesh were produced containing fibres 200 nm in diameter. The meshes were produced using a process called electrospinning, with parameters being optimised to ensure consistency in the mesh material.

“In order to deliver the antibiotics to a specific area, the antibiotics were embedded into the mesh, produced using a technique called electrospinning, which has gained considerable interest in the biomedical community as it offers promise in many applications including wound management, drug delivery and antibiotic coatings,” Associate Professor Koeper said.

“A high voltage is then applied between the needle connected to the syringe and the collector plate, which causes the polymer solution to form a cone as it leaves the syringe, at which point the electrostatic forces release a jet of liquid.

“Small charged nanoparticles altered the release of the antibiotics from the nanomesh. The addition of gold nanoparticles likely neutralised charge, causing the antibiotic to migrate toward the centre of the fibre, prolonging its release.”

The results indicate that dosages could be reduced in comparison to traditional drugs, which can also diminish potential side effects and complications.

“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.

“This research, as a proof of concept, suggests an opportunity for fabricating nanomeshes which contain gold nanoparticles as a drug treatment for antibiotics.”

Working with Flinders environmental health scientist Dr Harriet Whiley, the researchers studied how the release of the drugs affected the growth of E. coli. The in vitro study confirmed that colistin combined with negatively charged gold nanoparticles produced the most efficient nanomesh, significantly affecting bacterial growth.

The research team said that further investigation is needed to determine if other small charged particles affect the release of drugs and how these affect release over time. The stability of the mesh under different storage conditions, as well as the toxicological properties, also needs to be evaluated.