Throughout the animal kingdom, insects are known for being highly resistant to bacterial infections. Their bodies can produce proteins and peptides, which serve as their first line of defense against pathogens. Replicating this function can hold the key to developing new products with antibacterial properties that are more effective than conventional chemical treatments.
Unlocking the Secrets of Cicada Wings
Research professor Maya Endoh and associate professor Tadanori Koga from the Department of Materials Science and Chemical Engineering of Stony Brook University were inspired by a 2012 study describing the cicada's ability to puncture bacterial cells with deadly effects. Since then, they sought to replicate the nanostructure of cicada wings with directed self-assembly.
The researchers decided to use cicada wings since they have a good pillar structure. It is known that the cicada wings contain nanopillars with height and spacing that measures 150 nanometers. Scientists are also aware that a cicada wing can prevent the adhesion of bacteria, but its mechanism remains a mystery.
To address this challenge, Endoh and Koga tried to optimize the structure of cicada wings by controlling the size and height of the pillar as well as the spacing between them. Then they investigated the geometric parameter required for bacterial killing action.
The cicada wings were replicated by guest researcher Daniel Salatto from Brookhaven National Laboratory using a polymer, particularly polystyrene-block-poly(methyl methacrylate) diblock copolymer. Making the pillars bacteria-resistant is possible as the diblock polymer creates the nanostructure.
However, the research team is still baffled about how bacteria are eliminated by the nanopillars on their surface. For this reason, they sought the help of researcher Jan-Michael Carrillo from the Center for Nanophase Materials Sciences at the Department of Energy's Oak Ridge National Laboratory (ORNL). Carrillo provides large-scale, high-resolution molecular dynamics (MD) simulation for the nanoscience researchers using the Summit supercomputer at the Oak Ridge Leadership Computing Facility at ORNL.
The results of the simulation reveal that the strong interaction between the bacterium and the nanostructure substrate allows the lipid heads to absorb onto the hydrophilic surfaces and adjust the membrane shape to the pillar structure. It was also found that regardless of height, the pillar naturally kills the bacteria and cleans itself.
Potential Applications of Cicada Wings' Antibacterial Properties
Each cicada species has unique nanopillars with various sizes, shapes, and shapes. Nanoscale surfaces can be designed and manufactured using these useful properties.
New coatings inspired by cicada wings can develop surfaces with self-cleaning, antibacterial, and water-repellant properties. This can help improve the performance of medical equipment, optical instruments, sensors, and screens.
Aside from nanoscale surfaces, the antibacterial properties of cicada wings also inspired the development of nano-based food packaging. In a 2022 study, an Australian-Japanese team of scientists created a lab-made nanostructure that can effectively kill up to 70% of bacteria, extending the shelf life of food and minimizing waste from packaging.
RELATED ARTICLE: Nanoengineers Use Shark Skin and Dragonfly Wings as Inspiration in Developing Advanced Antibacterial, Antifouling Solutions
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