As the co-author of the article and a researcher at the Biological Institute of Jovan Haji ZRC of the SAZU explained to the Slovenian Press Agency Matjaž Gregorič, spiders have several types of silk, and the material properties of silk differ greatly between different types of spiders.
In a study published in a journal Communications Biology, the researchers focused on the species Darwin's Tree Spider, with a scientific name Caerostris darwini. She is known for building the largest known nets, which places them in a unique habitat for spiders, and they are built of the strongest silk, which according to Gregoric. "absolute tensile strength recorder" respectively "the amount of energy we have to put in to break a fiber".
It is a silk that they call in English "major ampullate"respectively MA-silk, and the thread that spiders build with this type of silk, is called the pull thread. This type of silk is the highest quality biological material in terms of tensile strength and surpasses many synthetic materials.
The main purpose of the research of Slovenian and American researchers was therefore to find out what could be the cause of such an unusually high quality yarn in this type of spiders. The researchers predicted that the answer lies in new or different proteins that contribute to the higher tensile strength of their silk.
According to Gregoric, spider silk is composed mainly of proteins. For MA-silk, however, is known to consist largely of two proteins that call it silk MaSp1 and MaSp2and in the study, researchers found that the silk of the Darwin tree spider is a third protein, which they named MaSp4a. This new protein has it regions, which are assumed to contribute to the greater elasticity of spider silk.
Different silk glands
In addition, the researchers also found that the silk glands of this species are clearly different from all the rest known so far. "Silk is created in the glands of the buttocks as a liquid yarn, and transforms into a solid state when pulled through the derivative. The properties of the glandular derivatives, such as their morphology and changes in pH, are also likely to contribute to the final material properties of silk. Therefore, we assume that the unique structure of the glandular derivatives of the Darwin tree spider is also linked to their unusually high-quality silk, " said Gregoric.
She led the research Jessica Garb from the University of Massachusetts Lowell in the US, who is also the first author of the article. In addition to US researchers, the study also involved Matjaz Kuntner z Of the National Institute of Biology and Biological Institute of Jovan Haji ZRC SAZU and Gregorič from Biological Institute Jovan Haji ZRC SAZU.
Where all the knowledge could be used
Research in the field of spider silk is already extremely lively today, and researchers are working to discover everything from patterns of its evolution and genetic background to how it can be synthesized successfully in the laboratory. According to Gregoric "today we don't even know the extent of possible use when one day we will be able to synthesize it really effectively in the lab".
Potential applications, according to Gregoric, could be used wherever nylon and rubber-like materials are used – materials that are somewhat elastic but nonetheless durable.
"Such materials are used in all parts of our lives, so future direct use could be, for example, in the manufacture of clothing and footwear, home decoration, pet installations, food packaging, car tires, military equipment, parachutes, ropes, tools and mechanical parts of engines. , 3D printing etc. "
Medicine is also a very interesting area of potential use. Silk is supposed to be biocompatible, so according to Gregoric, it could be used for natural sutures, it could be used to close wounds and tissues or as a lining of implants. Possible application Gregoric also said that it supports nerve regeneration and delivery of drugs in degradable capsules.