Watch out spiderman! We’ve found a way to create spider silk
Scientists from the RIKEN Center for Sustainable Resource Science (Wakō, Japan) have crafted a device capable of spinning artificial spider silk closely mirroring the physical and chemical properties of naturally produced spider silk.
The research, published in Nature Communications, showcases an eco-friendly breakthrough with far-reaching implications across various industries, including medicine.
Spider silk, renowned for its strength, flexibility, and light weight nature, has an unparalleled strength-to-weight-ratio. Pound for pound, spider silk is tougher than Kevlar and five times stronger than steel.
Beyond its mechanical prowess, spider silk is biocompatible and biodegradable, making it suitable for diverse applications, including medical uses. However, the challenge lies in the impracticality of large-scale silk harvesting from spiders, necessitating laboratory production.
The key to spider silk’s unique properties lies in its complex molecular structure, specifically the proper alignment of molecular substructures called beta sheets within silk fibers. Until now, mimicking this intricate architecture has posed a significant challenge for scientists.
To overcome this challenge, the RIKEN researchers adopted a biomimicry approach utilizing microfluidics: a technique involving the flow and manipulation of small fluid amounts through narrow channels.
The microfluidic device the team created resembles a small rectangular box with grooved channels. A precursor spidroin solution is positioned at one end, drawn towards the opposite end by negative pressure. This method subjects the spidroins to exact modifications in the chemical and physical environment within the microfluidic channels, enabling the self-assembly of silk fibers with the characteristic beta sheet alignment.
Through experimentation, the researchers identified optimal conditions, emphasizing the importance of negative pressure in pulling the spidroin solution for continuous silk fiber assembly with the correct beta sheet alignment.
“It was surprising how robust the microfluidic system was, once the different conditions were established and optimized,” commented co-author Ali Malay. “Fiber assembly was spontaneous, extremely rapid, and highly reproducible. Importantly, the fibers exhibited the distinct hierarchical structure that is found in natural silk fiber.”
Why is this relevant you ask? It’s all well and good for the next spiderman movie, but how can it help medicine and biotech?
The potential applications of artificially produced silk fibers are vast, offering environmental benefits by reducing the negative impact of current textile manufacturing practices. Moreover, the biodegradable and biocompatible nature of spider silk makes it a perfect candidate for biomedical applications, including sutures and artificial ligaments.
For example, a team at MIT (MA, USA) discovered an intriguing new property possessed by spider silk that could be employed in robotic muscles. Spider silk fibers respond dramatically to fluctuations in humidity. Above a certain level of relative humidity in the air, they suddenly contract and twist, providing a strong torsional force.
This finding is extremely promising for humidity-driven soft robotics, and for developing smart fabrics. Now combined with this new research at the RIKEN Center, robotics and smart fabrics could take a huge leap forward.
Keiji Numata, the team leader at the RIKEN Center for Sustainable Resource Science, envisions real-world impact, emphasizing the need to scale up the fiber-production methodology to assess the quality of artificial spider silk using various metrics for ongoing improvements. This research opens doors to sustainable and innovative solutions across industries, revolutionizing the production of spider silk with far-reaching implications for both the environment and biomedical advancements.