Researchers would love to understand the secret to the impressive properties of spider silk, which is super strong, super light, and super flexible. But despite years of research, no one has been able to replicate the silk’s properties. If scientists could produce a synthetic material with the same characteristics, it could replace materials such as Kevlar, polyester, and carbon fiber in different industries. Artificial spider silk could even be used to create lightweight and flexible bulletproof vests!
Irina Iachina, a postdoc and biophysicist from the Department of Biochemistry and Molecular Biology at the University of Southern Denmark, is among the researchers involved in this race to uncover the recipe for super silk. She has been fascinated by spider silk since her time as a master’s student at SDU and is currently researching the topic at the Massachusetts Institute of Technology in Boston with support from the Villum Foundation.
As part of her research, she is working closely with associate professor and biophysicist Jonathan Brewer at SDU, who specializes in using various types of microscopes to examine biological structures. For the first time, the researchers used an optical microscope to study the internal parts of spider silk without cutting or opening the silk. Their work has been published in the journals Scientific Reports and Scanning.
“We have used several advanced microscopy techniques, and we have also developed a new kind of optical microscope that allows us to look all the way into a piece of fiber and see what’s inside.”
Spider silk has been analyzed using various techniques, all of which have provided new insights. However, these techniques have drawbacks, as Jonathan Brewer points out. For example, they often require cutting the silk thread (also called fiber) open to obtain a cross-section for microscopic examination or freezing the samples, which can alter the structure of the silk fibers.
Irina Iachina said,
“We wanted to study pure and unmanipulated fibers that have not been cut, frozen, or manipulated in any way.”
The research team used less invasive techniques, such as Coherent Anti-Stokes Raman Scattering, Confocal Microscopy, Ultra-resolution Confocal Reflection Fluorescence Depletion Microscopy, Scanning Helium Ion Microscopy, and Helium Ion Sputtering, to examine the spider’s silk fiber. The studies showed that the fiber consists of at least two outer layers of lipids, or fats, with numerous fibrils running inside the fiber in a straight, tightly packed arrangement (see illustration). The fibrils have a diameter ranging between 100 and 150, which is too small to be measured with a regular light microscope.
Irina Iachina explained,
“They are not twisted, which one might have imagined, so now we know that there is no need to twist them when attempting to create synthetic spider silk.”
Iachina and Brewer work with silk fibers from the golden orb-web spider, Nephila Madagascariensis, which produces two types of silk:
- MAS: This silk is used to construct the spider’s web and for hanging on. Irina Iachina calls it the “spider’s lifeline.” It is very strong and has a diameter of about 10 micrometers.
- MiS: This silk is more elastic and has a diameter of about 5 micrometers. It serves as an auxiliary material for construction.
The duo’s analysis shows that the fibrils in MAS silk have a diameter of about 145 nanometers, while the fibrils in MiS silk have a diameter of about 116 nanometers. Each fibril is made up of proteins, and several different proteins are involved. These proteins are produced by the spider when it creates its silk fibers.
While it is important to understand how these strong fibers are created, producing them is challenging. Therefore, researchers often rely on spiders to produce the silk for them. But they can use computational methods, which is what Irina Iachina is currently working on at MIT.
“Right now, I am doing computer simulations of how proteins transform into silk. The goal is, of course, to learn how to produce artificial spider silk, but I am also interested in contributing to a greater understanding of the world around us.”
In-Article Image Creditssurprising details about the world's strongest spider silk via ANDERS BOE/UNIVERSITY OF SOUTHERN DENMARK with usage type - News Release Media
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