Scientists have developed a smart, bacteria-repelling coating based on resilin. This is an ultra-elastic protein that provides fleas with their legendary power. When this substance is applied to surfaces like medical implants or surgical tools, the Australian scientists found that engineered resilin forms nano-droplets that physically disrupt bacterial cells, including antibiotic-resistant strains like MRSA (Methicillin-resistant Staphylococcus aureus), without harming human tissue.
In RMIT University in Australia laboratory tests, the coating was 100% effective at keeping bacteria from sticking and forming biofilms, which is a key cause of infection after surgery.
Resilin is a protein found in insects and it is known for its remarkable elasticity and it is additionally resilient and biocompatible. It is the most efficient elastic protein known.
According to lead scientist Professor Namita Roy Choudhury this finding is a critical step towards their goal of creating smart surfaces that stop dangerous bacteria, especially antibiotic-resistant ones like MRSA, from growing on medical implants.
As an example of the associated medical concern, bacteria are often found on implants following surgery, despite sterilisation and infection controls. These organisms can lead to infections requiring antibiotics, but with antibiotic resistance becoming more common, new preventative measures are needed.
“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”, “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”, Choudhury observes.
She adds: “Antibiotic resistance has prompted greater interest in the area of self-sterilising materials and easy preparation of antibacterial surfaces.”
This leads into the motivation for the research: “Therefore, we designed this surface to completely prevent the initial attachment of the bacteria and biofilm formation to decrease the infection rates. These exceptional properties and non-toxic nature make resilin and resilin-mimetic proteins ideal for many applications requiring flexible, durable materials and coatings.”
In describing the applications, Choudhury says: “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.”
Potential applications
The medical applications for the research include spray coatings for surgical tools, medical implants, catheters and wound dressings. The researchers created several forms of coating from altered forms of resilin, then tested their interactions with E.coli bacteria and human skin cells in lab conditions.
The study showed how the altered proteins in nano droplet form known as coacervates were 100% effective at repelling the bacteria, while still integrating well with healthy human cells, a critical part of medical implant success. Once they come in contact, the coating interacts with the negatively charged bacterial cell membranes through electrostatic forces, disrupting their integrity, leading to leakage of cellular contents and eventual cell death.
Future work includes attaching antimicrobial peptide segments during recombinant synthesis of resilin-mimics and incorporating additional antimicrobial agents to broaden the spectrum of activity.
The research appears in the journal Advances in Colloid and Interface Science, titled “Nano-structured antibiofilm coatings based on recombinant resilin.”
