The spider web is known for its extreme mechanical properties, this natural fiber is more resistant than any other fiber made by man. It is twenty times finer than a human hair. The cloth or silk – as some scientists like to call it – has also been used in traditional medicine to stop bleeding and to improve wound healing. A team led by Anna Rising of the Department of Neurobiology at the Karolinska Institute in Sweden has managed to produce artificial spider web through bacteria that produce spider silk proteins.
Spider web is an attractive material, well tolerated when implanted in the fabrics, is light but stronger than steel, and is also biodegradable. However, spiders are difficult to maintain in captivity and they were small amounts of silk. Therefore, any large-scale production should involve the use of artificial silk proteins and spinning processes. A biomimetic spinning process (which mimics nature) is probably the best way to make fibers that resemble the actual spider web. Until now, this has not been possible because of the difficulties in obtaining water soluble spider silk proteins from bacteria and other production systems.
The spider web is made up of proteins that are stored as an aqueous solution in the silk glands, before you start spinning on a fiber. Researcher Anna Rising and colleagues Jan Johansson and Marlene Andersson of the Swedish University of Agricultural Sciences and the Karolinska Institute have previously shown that there is an impressive gradient – increasing or decreasing intensity of a variable magnitude, and curve representing it pH In the spider silk gland, and that this well-regulated pH gradient affects specific parts of the spider web proteins and ensures that the fiber forms are quickly fixed at a defined location of the fabric producing apparatus.
This knowledge has now been used to design an artificial spider silk protein that can be produced in large quantities in bacteria, making production viable and interesting from an industrial point of view. “To our surprise, this artificial protein is as water soluble as the natural spider silk proteins, which means that it is possible to keep soluble proteins in extreme concentrations,” says Anna Rising.
To mimic the spider web gland, the research team constructed a simple but highly efficient and biomimetric spinning apparatus – technological solutions inspired by nature’s designs – in which fibers can spin long kilometers only by reducing the PH.
“We have designed a process that recapitulates many of the complex molecular mechanisms of natural silk spinning. In the future this may allow the industrial production of artificial spider web for biomaterial applications or for the manufacture of advanced textiles,” said Anna Rising .
Researchers from the University of Dongsheng (China), Polytechnic University of Madrid (Spain), Oxford University (UK), KTH Royal Institute of Technology (Sweden), Uppsala University And the University of Lund (Sweden).