Australian engineers may have big new weapon in the fight against antibiotic resistance.

Antibiotic resistance is on track to cause up to ten million deaths a year by 2050, but the medical world has only been able to produce one or two new antibiotics in the last 30 years.

Researchers from the Melbourne School of Engineering are using chemistry to mimic biology and create new structures, which are inspired by small protein molecules produced by the body to fight against bacterial invasion.

“The problem with this is that over time bacteria mutate to protect themselves against antibiotics, making treatment ineffective,” says research engineer Professor Greg Qiao.

Professor Qiao and his team had been working with antimicrobial peptide polymers made from amino acids when they discovered an unexpected property of their polypeptides.

The team created a star-shaped polypeptide that was extremely effective at killing Gram-negative bacteria – a major class of bacteria known to be highly prone to antibiotic resistance.

Traditional antimicrobial peptides (AMPs) kill bacteria, but they are also very toxic to the body and tend to kill the host as well.

During in vitro studies so far, the star-shaped peptide polymer’s ability to kill superbugs has been shown to be better than that of antibiotics and linear AMPs, and they are non-toxic to human cells.

In fact, tests undertaken on red blood cells showed that the star-shaped polymer dosage rate would need to be increased by a factor of > 100 to become toxic.

In vivo tests using animal models have also shown that the star-shaped polymer is not only as effective in killing bacteria as antibiotics, but after bugs were mutated and antibiotics stopped working, they were still highly effective.

The full study is accessible here.