Antimicrobial resistance (AMR) has become a major global public health issue – threatening the effective prevention and treatment of a range of infections. It is listed by the World Health Organization among the top ten global public health threats facing humanity, as it is predicted to cause around 10 million deaths each year by 2050.
AMR arises when microorganisms evolve over time and no longer respond to medicines – making infections more difficult to treat and increasing the risk of disease spread, severe illness and death.
The emergence of widespread bacterial resistance against established antibiotics has deepened the urgency for the discovery of novel therapeutics.
Antimicrobial peptides (AMPs) are one of the most promising alternatives to conventional antibiotics – offering clear advantages such as slower emergence of resistance and broad- spectrum antimicrobial activity. For example, tyrothricin is a mixture of AMPs with activity against bacteria, fungi and some viruses.
Wound infection with antimicrobial-resistant bacteria can be particularly difficult to treat, as most systemically delivered antimicrobials do not reach sufficient levels at the infection site.
The local application of AMPs such as tyrothricin could help to overcome this problem – but the challenge of adequate drug delivery remains, as sufficient concentrations need to be maintained for long enough to clear the infection.
In a new study, published in the European Journal of Pharmaceutics and Biopharmaceutics, researchers develop electrospun drug-loaded wound dressings incorporating tyrothricin. 1
By parallel electrospinning, the team combined different ratios of water-soluble polyvinylpyrrolidone and water-insoluble methacrylate copolymer (Eudragit E). They systematically adjusted polymer ratios to optimise the wound dressings concerning their physicochemical properties, mechanical stability, release kinetics and biological compatibility.
They fabricated fiber mats constituting mechanically stable wound dressings with a controlled drug release profile, combining an initial burst release above the minimum concentration needed to inhibit bacterial growth and a subsequent prolonged antimicrobial effect of the active ingredient. They showed the tyrothricin-loaded fiber mats had antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermis, which are both common causes of wound infections.
The researchers used deionized water generated from an ELGA PURELAB® Flex 2 laboratory water purification system, minimising the risk of introducing contaminants that may affect their results.
In this study, the researchers successfully developed electrospun wound dressings for the local delivery of poorly water-soluble AMP tyrothricin. By parallel electrospinning of drug- loaded PVP fibers with Eudragit E fibers in varying concentrations, they developed intersecting fiber scaffolds with modified release properties. These systems enabled an enhanced aqueous solubility of tyrothricin while providing tuneable extended drug release kinetics.
Tyrothricin was released from the fibers and its antimicrobial performance was confirmed against two prominent wound pathogens in vitro.
Based on these encouraging results, the team is now planning to carry out further research to explore the incorporation of promising novel AMPs – as well as efficacy testing against antibiotic-resistant bacterial strains.
ELGA’s expert engineers, chemists and scientists are at the forefront of technological innovation. We continue to introduce game-changing features to the laboratory water market.
Dr Alison Halliday
After completing an undergraduate degree in Biochemistry & Genetics at Sheffield University, Alison was awarded a PhD in Human Molecular Genetics at the University of Newcastle. She carried out five years as a Senior Postdoctoral Research Fellow at UCL, investigating the genes involved in childhood obesity syndrome. Moving into science communications, she spent ten years at Cancer Research UK engaging the public about the charity’s work. She now specialises in writing about research across the life sciences, medicine and health.