According to UCL, nanofibres made of starch could be used in bandages to aid wound healing, as scaffolding for bone regeneration, and for drug delivery. However, they rely on starch being extracted from plant cells and purified, a process requiring much energy and water.
The researchers said a more environmentally friendly method is to create nanofibres directly from a starch-rich ingredient like flour, which is the basis for pasta.
In a new paper in Nanoscale Advances, the team describe making spaghetti 372nm across using electrospinning, a method in which threads of flour and liquid are pulled through the tip of a needle by an electric charge. The work was performed by Beatrice Britton, who carried out the study as part of her master’s degree in chemistry at UCL.
In a statement, co-author Dr Adam Clancy, UCL Chemistry, said: “To make spaghetti, you push a mixture of water and flour through metal holes. In our study, we did the same except we pulled our flour mixture through with an electrical charge. It’s literally spaghetti but much smaller.”
The novel nanopasta formed a visible mat of nanofibres about 2cm across. Each individual strand is too narrow to be clearly captured by any form of visible light camera or microscope, so their widths were measured with a scanning electron microscope.
Professor Gareth Williams, UCL School of Pharmacy, said: “Nanofibres, such as those made of starch, show potential for use in wound dressings as they are very porous. In addition, nanofibres are being explored for use as a scaffold to regrow tissue, as they mimic the extra-cellular matrix – a network of proteins and other molecules that cells build to support themselves.”
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Dr Clancy said: “Starch is a promising material to use as it is abundant and renewable – it is the second largest source of biomass on Earth, behind cellulose – and it is biodegradable, meaning it can be broken down in the body.
“But purifying starch requires lots of processing. We’ve shown that a simpler way to make nanofibres using flour is possible. The next step would be to investigate the properties of this product. We would want to know, for instance, how quickly it disintegrates, how it interacts with cells, and if you could produce it at scale.”
Electrospinning using a starch-rich ingredient such as white flour is more challenging than using pure starch, as the impurities – the protein and cellulose – make the mixture more viscous and unable to form fibres.
In electrospinning, the needle in which the mixture is contained and the metal plate upon which the mixture is deposited form two ends of a battery. Applying an electrical charge makes the mixture complete the circuit by streaming out of the needle on to the metal plate.
The researchers used flour and formic acid rather than water, as the formic acid breaks up the helices that make up starch. UCL said this is because the layers of helices stuck together are too big to be the building blocks of nanofibres.
The formic acid then evaporates as the noodle moves through the air to the metal plate.
The researchers also had to carefully warm up the mixture for several hours before slowly cooling it back down to make sure it was the right consistency.
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