Genetically Modified Maggots to Heal Wounds Faster

North Carolina State University researchers have genetically engineered maggots to produce and then secrete a human growth factor which is known to help the wound healing process by stimulating cell growth and survival.

In a proof of concept study, the researchers have showed that the genetically modified larvae of a green bottle fly (Lucilia sericata) can produce and secrete a human growth factor -BB (PDGF-BB), a molecule that helps promote cell growth and wound healing.

Lab-raised green bottle fly larvae were used in a special type of maggot debridement therapy (MDT), where fly larvae are applied to non-healing wounds, such as diabetic foot ulcers, to promote wound healing. Maggots have shown to clean the wound, remove all dead tissue, and secrete antimicrobial factors. The treatment is very cost-effective and approved by the Food and Drug Administration.

The study actually applied two techniques. The first technique focused on application of heat to start the production of PDGF-BB in transgenic green bottle flies. The human growth factor was readily traced in certain structures after the larvae were applied high heat - about 37 degrees Celsius - but PDGF-BB was not detected in maggot excretions or secretions, thus it was unworthy of clinical use.

The second technique was more effective. The flies were engineered in such a way that they only produced PDGF-BB when raised on a diet without the antibiotic tetracycline. PDGF-BB was produced at very high levels in the larvae and it was found in the excretions and secretions of maggots.

"A vast majority of people with diabetes live in low- or middle-income countries, with less access to expensive treatment options," Max Scott, a North Carolina State professor of entomology said. According to Scott, the researchers see the results as a proof of principle study for the future developments. He further explains that "the long-term aim of developing a cost-effective means for wound treatment" is to save people from amputation and the harmful effects of diabetes and other diseases.