Researchers led by Keiji Numata at the RIKEN Center for Sustainable Resource Science in Japan, along with colleagues, have succeeded in creating a device that spins artificial spider silk that closely matches what spiders naturally produce.
A new device is able to mimic natural spider silk production, offering a strong, flexible and eco-friendly sustainable alternative for the textile industry. The artificial silk gland was able to re-create the complex molecular structure of silk by mimicking the various chemical and physical changes that naturally occur in a spider’s silk gland. This eco-friendly innovation is a big step towards sustainability and could impact several industries.
Famous for its strength, flexibility, and lightweight, spider silk has a tensile strength that is comparable to steel of the same diameter, and a strength-to-weight ratio that is unparalleled. Added to that, it’s biocompatible, meaning that it can be used in medical applications, as well as biodegradable.
Large-scale harvesting of silk from spiders has proven impractical for several reasons, leaving it up to scientists to develop a way to produce it in the laboratory. Spider silk is a biopolymer fibre made from large proteins with highly repetitive sequences, called spidroins. Within the silk fibres are molecular substructures called beta sheets, which must be aligned properly for the silk fibres to have their unique mechanical properties. Re-creating this complex molecular architecture has confounded scientists for years.
RIKEN scientists took a biomimicry approach. Aumata explains, “In this study, we attempted to mimic natural spider silk production using microfluidics, which involves the flow and manipulation of small amounts of fluids through narrow channels. Indeed, one could say that the spider’s silk gland functions as a sort of natural microfluidic device.”
The device developed by the researchers looks like a small rectangular box with tiny channels grooved into it. Precursor spidroin solution is placed at one end and then pulled towards the other end by means of negative pressure.
As the spidroins flow through the microfluidic channels, they are exposed to precise changes in the chemical and physical environment, which are made possible by the design of the microfluidic system. Under the correct conditions, the proteins self-assembled into silk fibres with their characteristic complex structure.
“It was surprising how robust the microfluidic system was, once the different conditions were established and optimised,” says Senior Scientist Ali Malay, one of the paper’s co-authors. “Fibre assembly was spontaneous, extremely rapid, and highly reproducible. Importantly, the fibres exhibited the distinct hierarchical structure that is found in natural silk fibre.”
The ability to artificially produce silk fibres using this method could provide numerous benefits. Not only could it help reduce the negative impact that current textile anufacturing has on the environment, but the biodegradable and biocompatible nature of spider silk makes it ideal for biomedical applications, such as sutures and artificial ligaments.
Device mimicking natural spider to produce silk without silk spider
