Gas inside us could fight wound infections, moth study shows

A gas naturally produced by our own bodies could one day help treat skin and wound infections, potentially offering a new approach alongside conventional antibiotics.

A new study led by scientists at the University of Reading found that tiny particles releasing nitric oxide helped nine in ten infected wax moth larvae survive bacterial infections, compared with around six in ten that were not treated. 

Published today (Tuesday, 3 November) in the Journal of Drug Delivery Science and Technology, the findings could give doctors another treatment option for infected wounds that antibiotics struggle to clear.

Professor Vitaliy Khutoryanskiy, who led the research from the University of Reading’s School of Pharmacy, said: “With bacteria becoming harder to kill with antibiotics, we urgently need treatments that work in a different way. 

“Nitric oxide attacks germs on several fronts at once, so bacteria find it much harder to become resistant. The challenge is to find ways to store it and release it slowly. 

“We went beyond killing bacteria in the lab and showed our particles could help infected wax moth larvae survive. Wax moth larvae are becoming increasingly important for testing new treatments, helping us understand how well they work while reducing the need for experiments on mice and rats.”

Moths instead of mice

To carry out the study, the research team, which involved scientists from Al-Farabi Kazakh National University (Kazakhstan), first infected wax moth larvae with bacteria that cause skin infections. One hour later, scientists injected each larva with particles that release nitric oxide. Nitric oxide breaks down too quickly to use as a medicine on its own, so the team packed it into particles far smaller than a speck of dust that let it out slowly over several hours.

The larvae were checked for three days, and most deaths among untreated larvae came within the first day. In separate tests in glass flasks, the particles left between 10,000 and 100,000 times fewer bacteria after a day than flasks with no treatment. More studies are needed before the particles could become a treatment for people.

Wax moth larvae were used in this study instead of mice or rats. Each larva weighs about a quarter of a gram, yet its body fights germs in ways that share features with humans. Scientists can check both whether a treatment is safe and whether it works in a living creature, while relying less on experiments with mammals. Professor Khutoryanskiy’s team is developing tests that use insects, worms and other animals without backbones to study the safety and effectiveness of new medicines and drug delivery systems, helping to reduce reliance on experiments involving mammals.