Technology and nature are not always opposing forces: in fact, many life-changing technologies have been inspired by the natural world. The inventor of the Velcro fastener, for example, was inspired by the prickly seeds that clung to his dog’s fur after their walks. Now more than half a decade later, A*STAR researchers have made a similarly unlikely connection—taking inspiration from insect wings to combat bacteria.
In the fight against bacteria, using harsh chemicals to disinfect high-traffic public areas and prevent the spread of disease isn’t always ideal, said Yugen Zhang, Senior Principal Investigator and Group Leader at A*STAR’s Institute of Bioengineering and Bioimaging (IBB).
“Prolonged usage of these chemicals may induce the development of drug-resistant microbes, rendering any reapplication ineffective,” Zhang explained. As an alternative, Zhang’s team looked to the naturally bacteria-killing cicada wings as summarised by Zhang and fellow IBB scientist Siti Nurhanna Riduan in a recent article in Acc Chem Res. Cicada wings are covered with sharp microscopic needle-like projections capable of bursting microbe cell walls, sparking the scientists’ hypothesis that synthetic nanomaterials with similar architectures could mimic its antimicrobial effect.
“Similar to cicada wings, our zinc-based nanostructure surfaces kill microbes by physically rupturing the cell membrane,” said Zhang. The materials used to design the nanosurfaces were intentionally selected to boost self-disinfection.
“The zinc component present on the surface releases reactive oxygen species,” Zhang explained, adding that this creates a halo effect to wipe out nearby bacteria, even those not in direct contact with the surface.
In their study, the researchers describe how they developed an innovative way to fabricate these historically difficult-to-manufacture complex nanostructured materials. They also showed that surface chemistry strongly influenced the microbe-killing effect: positively charged surfaces acted like a magnet to attract negatively charged bacteria, which were 'popped' by the nanoneedles.
The researchers’ work opens doors for chemical-free options for self-disinfecting surfaces that can be used in everything from walls and doorknobs to wound dressings. Two spin-off companies, Polymore Greentech and Protogen, are already working to commercialise this technology, with more on the way.
“We are constantly on the lookout for new ideas and commercialisation opportunities, to enhance protection against infectious diseases,” concluded Zhang.
The A*STAR researchers contributing to this research are from the Institute of Bioengineering and Bioimaging (IBB).