University of Reading: NO-releasing nanoparticles helped 9 in 10 infected moth larvae survive

Researchers at the University of Reading (UK), together with colleagues from Al-Farabi Kazakh National University (Kazakhstan), found that nanoparticles releasing nitric oxide (NO) helped nine in ten infected larvae of the greater wax moth (Galleria mellonella) survive a bacterial infection, according to Nauka w Polsce, citing the Journal of Drug Delivery Science and Technology. In the untreated group roughly six in ten larvae survived. naukawpolsce.plNauka w Polscenaukawpolsce.plOpen source ↗ The study was led by Prof. Vitaliy Khutoryanskiy.

Nitric oxide is produced naturally in the human body and works as a signalling molecule. Among other things, it takes part in regulating circulation, immunity and the transmission of nerve impulses. The new results suggest that in the future it might be used alongside conventional antibiotics to treat infected wounds.

Experiment: infection and slow NO release

The team infected the larvae with bacteria that cause skin infections. One hour later, each larva received particles that release NO. Because the gas decomposes too quickly to be used as a standalone drug, the researchers enclosed it in PEGylated organosilica nanoparticles containing S-nitrosothiols, which released the gas slowly over several hours.

The larvae were observed for three days. Most of those in the untreated group died within the first day. naukawpolsce.plNauka w Polscenaukawpolsce.plOpen source ↗

Wax moth larvae have long been used in studies of toxicity, infections and antibiotic efficacy in place of mammals. They are cheap to rear, have a short life cycle, and can be kept at 37 °C, the temperature preferred by human pathogens. Their tissues are easy to collect, and their immune system resembles the human one in many respects.

Bacterial counts and limits of the result

In separate tests, bacterial counts after one day in samples treated with NO-releasing particles were 10,000 to 100,000 times lower than in untreated samples.

According to Khutoryanskiy, NO attacks microbes on several fronts at once, which makes it considerably harder for bacteria to develop resistance. Finding a way to store the gas and release it slowly remains a challenge. He added that such larvae make it possible to assess the efficacy of new therapies while reducing the need for experiments on mice and rats. naukawpolsce.plNauka w Polscenaukawpolsce.plOpen source ↗

The authors state that further research is required before these particles can be considered for use in human therapy.