BioSteel was a trademark name for a high-strength based fiber material made of the recombinant spider silk-like protein extracted from the milk of transgenic goats, made by Nexia Biotechnologies, and later by the Randy Lewis lab of the University of Wyoming and Utah State University. 
The company had created lines of goats to produce recombinant versions of either the MaSpI (Major ampullate spidroin I or dragline I from Nephila clavipes, the golden orb weaver) or MaSpII (Major ampullate spidroin 2 or dragline 2 from Nephila clavipes) dragline silk proteins in their milk. When the female goats lactate, the milk, containing the recombinant silk, was to be harvested and subjected to chromatographic techniques to purify the recombinant silk proteins.
The purified silk proteins could be dried, dissolved using solvents (DOPE formation) and transformed into microfibers using wet-spinning fiber production methods. The spun fibers were reported to have tenacities in the range of 2 - 3 grams/denier and elongation range of 25-45%. The "Biosteel biopolymer" had been transformed into nanofibers and nanomeshes using the electrospinning technique.
Nexia is the only company which has successfully produced fibres from spider silk expressed in goat's milk. The Lewis lab has produced fibers from recombinant spider silk protein and synthetic spider silk proteins and chimeras produced in both recombinant E. coli and the milk of recombinant goats, however, no one has been able to produce the silk in commercial quantities thus far. The Company was founded in 1993 by Dr. Jeffrey Turner and Paul Ballard, and was sold in 2005 to Pharmathene.
Research has since continued with the help of Randy Lewis, a professor formerly at the University of Wyoming and now at Utah State University. He was also able to successfully breed spider goats in order to create artificial silk. There are now about 30 spider goats at a university-run farm.
Applications of artificial spider silk could include using it for artificial ligaments and tendons, bulletproof vests, and improved car airbags.
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