Spiders n Goatsgreenspun.com : LUSENET : Freedom! self reliance : One Thread
I heard about this some time ago, but saw this article and thought I'd share it with you. I think it's creepy. What are your thoghts?
Scientists Spin Silk From Milk
By RANDOLPH E. SCHMID, Associated Press Writer
WASHINGTON (AP) - By transplanting genes from a spider into cow and hamster cells, scientists have caused those cells to produce the protein that makes spider silk, a step that could point the way to commercial production of the tough fiber.
Spider silk has long been admired for its strength and durability and producing it has been a goal of researcher. They anticipate a range of uses, from surgical thread to soft body armor.
It hasn't been possible to develop ``spider farms,'' however, leading researchers to seek other means of producing the silk.
The process developed by Nexia Biotechnologies Inc., of Montreal, Quebec, and U.S. Army researchers in Natick, Mass., has produced small amounts of silk so far.
But Nexia President Jeffrey Turner says he can increase production to commercial scale using goats that would produce the silk protein in their milk.
In the work reported on in Friday's issue of the journal Science, researchers used cells removed from cows and hamsters.
Genes that code orb-web spiders to produce dragline silk - one of the strongest types - were transplanted into the mammal cells, which then began producing the proteins that can be spun into spider silk.
The resulting fiber was similar to real spider silk, though not as strong, Turner said in a telephone interview.
Randolph V. Lewis of the University of Wyoming, who has done similar research, said this is the first time cells from mammals have been induced to produce spider silk, though it has been done previously in bacteria and yeast.
He said the results are significant because the Nexia protein is larger than others have been able to produce.
``They've actually spun reasonably good fibers compared to natural fiber,'' he said.
It's also significant, Lewis said, that the fiber was produced in water-based conditions. Other attempts to duplicate spider silk have required use of harsh chemicals that would not be practical to work with on a large scale, Lewis said.
Jean Herbert of the Army's Soldier Biological Chemical Command also hailed the production of the fiber in water as a breakthrough.
Spider silk is of interest to researchers because, by weight, it is stronger than steel and tougher than the artificial fibers currently used in body armor. Nexia has trademarked the name BioSteel for its fiber.
While Turner said the silk produced so far isn't as strong as the natural fiber it's about equal in toughness. Toughness is the reason silk makes good neckties, for example; it can be bent and twisted repeatedly without breaking.
The silk protein is produced in a liquid about the thickness of maple syrup, Turner said. From that the filament was drawn out into silk fibers.
In the lab work, Turner explained, the cow and hamster cells line long hollow tubes. They are fed from one end with a growth medium and the silk protein comes out the other end.
The tubes are called Charlottes, after the spider in the book ``Charlotte's Web.''
That process can't be scaled up to industrial levels, however, Turner said. Thus, his company is now turning to goats, inserting the spider gene into them with the goal of producing the protein in large quantities in their milk.
-- Doreen (firstname.lastname@example.org), January 19, 2002
OK, so what are they going to do with these animals after they have lived out their usefulness? Sell them to be butchered just like a normal animal? What would they do with any excess milk, if there was any? Sell it to be drunk by unsuspecting customers? I'm suspicious of this whole thing.
-- Green (email@example.com), January 20, 2002.
Although the thought of spiders may be creepy, the spider silk protein harvested from Nexia Biotechnologies transgenic goats is very useful. Furthermore, the transgenic goat does not suffer; the goats function as normally as does any goat. The only difference is that the goat's milk has two extra proteins found in the golden orb spider "dragline" silk. These proteins are rich in alternating blocks of alanine and glycine amino acids. The alanine blocks form crystalline structures that give dragline spider silk its strength, while less orderly glycine blocks provide the silk’s elasticity. Producing milk with spider silk protein does not hurt the goat. The goat lives as normal a lifespan as does any milk goat and the spider silk protein is biodegradable. The spider genes are faithfully passed on among the experimental goats. And that means producing more artificial silk might be as simple as breeding more of the genetically-enhanced goats naturally. Once the goat embryo is genetially engineered to produce the spider silk protein, the mature goat can be mated and the female offspring will also produce the spider silk protein in her milk.
There are several benefits to having a goat produce milk with the the orb spider "dragline" silk protein. The spider silk protein may be extracted from the goat milk and spun into fibers. Nexia Biotechnologies, the company with the transgenic goats, has partnered with Acordia Specialty Fibers which extracts the spider silk protein from the goats and spins it into fibers. The resultant fiber, dubbed BioSteel, has several important spplications such as surgical sutures, surgical mesh, surgical ligaments and ballistic fiber for body armor.
Spider silk has long been admired by material scientists for its unique combination of toughness, strength, flexibility, lightness and biodegradability. With a thickness of one tenth the size of a human hair and a tensile strength of 400,000 lb. per sq. in., spider silk is one of the strongest materials on earth that can be woven into a fiber. Weight for weight it is five times stronger than steel. Researchers estimate that the strongest spider silk can withstand up to 600,000 pounds (272,000 kilograms) per square inch. BioSteel stretches better than nylon which is elastic but withstands much less stress.
BioSteel is well suited to making ballistic body armor. BioSteel is three times as strong as Kevlar - a petroleum-based material used to make bullet-proof vests. The other alternative to Kevlar is carbon nanotubes which are still too expensive to be practical.
BioSteel is ideal for special surgical applications such as sutures, mesh and braided ligament. For sutures requiring minimal scar tissue formation such as in opthalmic, neurological and reconstructive procedures, the fineness and knot security are important and Biosteel sutures are superior. Meshes are used to repair hernias and other than Biosteel there is no artificial ligament replacement material.
Furthermore, Nexia manufactures tPA (tissue plasminogen activator) in the goats. TPA is used to dissolve blood clots in patients who suffer a heart attack or stroke.
Finally, Nexia manufactures Protexia, a recombinant version of butyrylcholinesterase (BChE). BChE is present in minute quantities in blood; however, its protective capability is quickly overrun by a nerve agent challenge such as organophosphate (OP) agents (e.g. sarin). A recombinant version of BChE, such as Protexia, is essential since plasma derived sources would not be sufficient. Protexia makes it practical, for the first time, to protect large numbers of people from chemical weapons.
-- Cheryl Young (firstname.lastname@example.org), August 02, 2004.