Spider silks, the ecological materials of tomorrow?

Dec 04, 2004

Spider silks could become the intelligent materials of the future, according to a review article published this month in the journal Microbial Cell Factories. The characteristics of spider silk could have applications in areas ranging from medicine to ballistics.
This becomes possible because Hebrew scientists, for the first time anywhere, have succeeded in producing self-assembled spider web fibres under laboratory conditions, outside of the bodies of spiders.

The distinctive toughness of spider silk could allow manufacturers to improve wound-closure systems and plasters, and to produce artificial ligaments and tendons for durable surgical implants. The silk could also be woven into strong textiles to make parachutes, body armour, ropes and fishing nets. A whole range of ecological materials could emerge from the industrial production of spider silk.

Thomas Scheibel, from the Department of Chemistry of the Technische Universität in München explains that there are currently over 34,000 described species of spider, each with a specific tool-kit of silks with different mechanical properties serving specific purposes.

For example, major ampullate silk, a very tough silk with a tensile strength comparable to Kevlar, is used for the primary dragline or scaffolding of the spider’s web. Minor ampullate silk with its very low elasticity is used to reinforce the web, while the strong and stretchy flagelliform silk forms the capture spiral of the web.

Biotechnologists are currently analysing the properties of silk proteins and how they assemble into threads. Knowing exactly how silk fibers are formed and what mechanical properties result from different assembly processes could allow the manufacture of artificial spider silks with special characteristics such as great strength or biochemical activity.

“The future objective might not be to prepare identical copies of natural silk fibers, but rather to capture key structural and functional features in designs that could be useful for engineering applications” explains the author.

Spiders are territorial and cannibalistic and so impossible to farm. The only way to produce large quantities of silk is to engineer and insert silk genes into other cells or organisms. But this has been complicated by the nature of the genes, which include many repeated sequences and rely on a different codon reading system from ours. However, in recent studies parts of the genes were successfully inserted into the bacterium E. coli, mammal and insect cells, which in turn produced silk proteins.

“Using ‘protein engineering’ based on knowledge achieved from investigations of the natural silks, artificial proteins can be designed that allow bacterial synthesis at high yields” writes Scheibel in the article*.

Engineering new proteins would also allow the design of completely new types of silk fiber, which could assemble with biochemically or biologically active groups into new types of mesh. These ‘intelligent’ materials would then be able to carry out enzymatic reactions, chemical catalysis or electronic signal propagation, for example.

Before this can be achieved, the spinning of proteins into fibers has to be resolved. So far there have been a few attempts at spinning silk on silicon micro-spinnerets. The outcomes have been promising but are far from matching naturally produced silks. For the moment the fibers produced are too wide, with diameters ranging from 10 to 60mm, compared with diameters of 2.5 to 4.0mm in natural fibers.

Explore further: Search continues at ancient Greek burial mound (Update)

add to favorites email to friend print save as pdf

Related Stories

Patent issued for substance with medical benefits

Nov 04, 2014

A novel jelly-like substance developed by Kansas State University researchers was recently issued a U.S. patent. The substance may be used for biomedical applications, ranging from cell culture and drug delivery to repairing ...

We shouldn't fear the big, bad wolf spider

Oct 29, 2014

Longtime University of Cincinnati professor George Uetz studies how the environment influences the evolution of behavior through researching animal behavior and ecology. Uetz's research focuses on spiders, ...

The ultimate biofilament: Hagfish slime

Sep 25, 2014

(Phys.org) —Perhaps the worst fate to be had in the sea is to be slimed by the hagfish. The proteinaceous goo they secrete has gotten many a hagfish out of bind by gumming up the gills and suffocating a ...

Recommended for you

When shareholders exacerbate their own banks' crisis

Nov 21, 2014

Banks are increasingly issuing 'CoCo' bonds to boost the levels of equity they hold. In a crisis situation, bondholders are forced to convert these bonds into a bank's equity. To date, such bonds have been ...

Trouble with your boss? Own it

Nov 21, 2014

Don't get along with your boss? Your job performance may actually improve if the two of you can come to grips with the poor relationship.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.