Researchers have developed a new method for preventing bacteria from adhering to surfaces, such as medical devices. It relies on the unique properties of resilin, a natural insect protein that enables fleas to jump hundreds of times their body length.
Resilin is a super-elastic protein produced by many insects, which enables them to jump and stretch their wings. It’s what enables some species of fleas, for example, to jump up to 200 times their body length.
Led by researchers from RMIT University in Melbourne, Australia, a new study examining the applicability of a resilin-mimicking compound in healthcare found that it can be used to form an antibacterial coating that fully blocks bacteria from attaching to a surface.
“This work shows how these coatings can be adjusted to effectively fight bacteria – not just in the short term, but possibly over a long period,” said the study’s corresponding author, Professor Namita Roy Choudhury, from RMIT’s School of Engineering.
Resilin-mimetic polypeptides (RMPs) are engineered proteins designed to mimic the properties of natural resilin, namely, its remarkable elasticity and biocompatibility. Because they’re engineered, they can be tailored to fit a specific purpose. In the present study, the researchers set out to utilize these properties to create a new, unique class of antibacterial surface coating.
“These exceptional properties and non-toxic nature make resilin and resilin-mimetic proteins ideal for many applications requiring flexible, durable materials and coatings,” Choudhury said. “These applications range from tissue engineering and drug delivery to flexible electronics and sports equipment, but this is the first work published on its performance as an antibacterial coating.”
The researchers fabricated four differently composed resilin-based surface coatings and tested the mechanical properties of each, including their effectiveness in resisting bacterial growth. The coatings were exposed to E. coli, a common cause of hospital-acquired bacterial infections, and then incubated for 24 hours.
One of the coatings, a coacervate, repelled 100% of bacteria, stopping them from attaching to surfaces while being non-toxic to human cells. A coacervate is a soft, spherical, nano-sized droplet made from proteins (resilin in this case) that clump together in water, forming a separate phase (like tiny blobs), which coats surfaces and influences how cells or bacteria interact with them.
“Unlike antibiotics, which can lead to resistance, the mechanical disruption caused by the resilin coatings may prevent bacteria from establishing resistance mechanisms,” said lead author Dr Nisal Wanasingha, an academic researcher at RMIT. “Meanwhile, resilin’s natural origin and biocompatibility reduce the risk of adverse reactions in human tissues and, being protein-based, are more environmentally friendly than alternatives based on silver nanoparticles.”
The ability to tailor the function of RMPs to fit what’s needed is a definite plus, according to the researchers.
“These early results are very promising as a new way to help improve infection control in hospitals and other medical settings, but now more testing is needed to see how these coatings work against a wider range of harmful bacteria,” said study author Professor Naba Dutta, from RMIT’s School of Engineering.
Once the researchers have broadened the coating’s spectrum of bug-killing activity, the transition from the lab to clinical use will follow. This requires the coating’s formula to be stable and scalable before its safety and effectiveness are tested in humans.
The study was published in the journal Advances in Colloid and Interface Science.
Source: RMIT