The amazing properties of spider silk

BILLAUD Camille - M1 EFTIS

Plan

• What are the amazing properties of spider silk?

• What could we do with spider silk?

• How to reproduce artificially spider silk?

What are the amazing properties of spider silk?

• Stronger and more elastic than steelMore resistant than kevlar

• Insoluble in water

• Light

Spider silk is :

• Can absorb as much water as wool

• A spider doesn't swing in its thread and spins it in a straight line Shape memory

What could we do with spider silk?

• In the army : bulletproof clothes

• In medicine :stronger surgical sutures artificial tendons artificial ligaments

• In sport :stronger parachutes

But we can’t breed spiders because they kill each other …

So, what is the solution ?

So spider silk is very useful

GRRR !!!Yum Yum !

How to reproduce artificially spider silk?

Scientists have studied how spiders make their silk:

Silk proteins are long molecules

form a viscous solution

passes in a very fine canal of spider’s gland

molecules become aligned

The spider stretches the gel before it dries

viscosity drops by a factor of 500 or more…

• The alignment of protein fibers • The stretching by the spider• The drying

that gives silk threads their amazing strength

So, it’s the combination of the three things :

The problem is how to produce the spider fiber silk proteins ?

Scientists know how to stretch and dry the fiber.

One of the ideas is described in the following video :

http://www.youtube.com/watch?v=fRTZMhYWKmY&NR=1

One of the ideas is : to produce the spider silk proteins in the milk of goats

Transgenic goats produce in their milk spider silk proteins !

The spider silk genes are introduced into goat embryos

The embryos are implanted in surrogate mothers

At birth, kids are carriers of spider silk genes !!

Proteins are separated from the milk and purified

They pass under pressure in microscopic holes to force them to align.

The thread is stretched to give it its mechanical properties

We obtain transgenic thread !

To obtain transgenic thread :

Conclusion

• These synthetic fibers could be marketed to do surgical sutures

• But they are not strong enough to produce bulletproof jackets so it remains to improve the quality of the fiber

• The number of transgenic goats is insufficient to produce artificial silk in industrial quantity

Bibliography

http://www.futura-sciences.com/fr/news/t/recherche/d/le-secret-des-proprietes-exceptionnelles-du-fil-daraignee_8589/

http://www.futura-sciences.com/fr/news/t/physique-1/d/le-fil-daraignee-ou-larme-de-la-biotechnologie_4934/

http://www.radio-canada.ca/actualite/decouverte/reportages/2002/09-2002/29sept_2002/araignee.html

http://www.eurekalert.org/pub_releases/2006-10/miot-mep103006.php

http://www.youtube.com/watch?v=fRTZMhYWKmY&NR=1

Thank you and bye bye !

Does anyone have questions ?