A recent study conducted by scientists at RMIT University has uncovered a promising approach to combat drug-resistant superbugs, including fungi, by drawing inspiration from the bacteria-killing spikes found on insect wings. With the growing global concern over drug-resistant infections, this research could provide a breakthrough in addressing this pressing healthcare challenge. In medical procedures involving implants like titanium hips or dental prostheses, the risk of infection is a significant concern.
To mitigate this risk, doctors often employ various antimicrobial coatings, chemicals, and antibiotics. However, these conventional approaches frequently fail to combat antibiotic-resistant strains and may even contribute to the development of resistance. To tackle these challenges head-on, researchers at RMIT University have developed a microscale pattern of spikes that can be etched onto the surface of titanium implants and other materials.
This innovative approach offers a drug-free means of protection against both bacteria and fungi. Their study, published in Advanced Materials Interfaces, specifically tested the efficacy of these modified titanium surfaces in combating multi-drug-resistant Candida, a potentially lethal fungus responsible for a significant proportion of hospital-acquired medical device infections.
The specially designed spikes, each resembling the height of a bacteria cell, could destroy approximately half of the Candida cells upon contact. Importantly, the remaining cells that weren’t immediately destroyed were rendered nonviable due to the injuries they sustained, preventing them from reproducing or causing infections.
Dr. Denver Linklater, the lead postdoctoral researcher, explained that metabolic analysis of protein activity showed that the injured Candida cells were effectively incapacitated. Even after seven days, these cells could not recover in a non-stress environment and eventually underwent programmed cell death, known as apoptosis. This groundbreaking surface also demonstrated its effectiveness against common pathogenic bacteria, including golden staph, in an earlier study published in Materialia.
Distinguished Professor Elena Ivanova, the group leader, emphasized that these findings shed light on the design of antifungal surfaces to prevent biofilm formation by dangerous multi-drug-resistant yeasts. Importantly, the study suggests that resistance to these surfaces may not develop, as cells that survive initial contact ultimately die, either by rupture or programmed cell death.
Over the past decade, significant strides have been made in designing surfaces capable of killing superbugs upon contact. Nevertheless, the challenge of finding the right surface patterns that can eliminate all microbes to prevent resistance remains ongoing. This study suggests that it might not be necessary for all surfaces to immediately eradicate all pathogens upon contact, as long as the surfaces induce programmed cell death in the surviving cells, ensuring their demise.
RMIT’s Multifunctional Mechano-biocidal Materials Research Group has been at the forefront of developing antimicrobial surfaces inspired by the nanopillars found on dragonfly and cicada wings. These nanopillars have the unique ability to pull bacteria apart when they settle on the wings, leading to fatal ruptures in their membranes. Replicating this natural phenomenon, Ivanova’s team has spent the last decade creating nanopatterns of their own.
The latest advancement was achieved using a plasma etching technique to create antibacterial and antifungal patterns on titanium surfaces. According to Ivanova, this relatively simple etching technique has the potential for broad applications across various materials and industries. She noted that it could be optimized and applied not only to medical devices but also to dental applications and materials used in food production and agriculture, such as stainless-steel benches.
Phuc Le, the lead author of the study and a joint Ph.D. candidate with RMIT and the ARC Research Hub for Australian Steel Manufacturing, highlighted the value of collaborating with industry partners like BlueScope Steel. Their insights and practical experience have helped shape the research into solutions that can address real-world challenges. While the studies are in their early stages, there is promising potential for product optimization and practical implementation.
RMIT University’s innovative approach to combatting drug-resistant superbugs through surface modifications offers a ray of hope in the ongoing battle against these dangerous pathogens. By drawing inspiration from nature’s design, this research could lead to safer medical procedures and a broader range of applications across various industries.
