Spider silk

A North Carolina biotech company is using spider DNA to transform silkworms to produce spider silk, a fiber tougher, lighter and more flexible than most fibers.

TRANSCRIPT

Up next, we go to North Carolina, where a biotech company is using spider DNA to transform silkworms to produce spider silk, a fiber tougher, lighter, and more flexible than most fibers.

Here's the story.

In a nondescript metal-framed building in an industrial park in Charlotte, the ultimate textile target may finally be reached.

These are all cocoons from silkworms.

They're ordinary standard silk that we keep here for testing, but it's the same.

So, this fiber is, as you can see, a lot thinner than the hair on your head.

But this is a mile long inside this cocoon.

A mile long?

A mile long.

A mile long of a continuous fiber.

The target is silk.

It has been collected like this from the cocoon of the silkworm for thousands of years.

The material is prized for its beauty and its texture.

But these are not the typical silkworms.

This one right here, one of the parents tested out at full-strength spider silk.

So I have great hopes, and they just hatched this morning.

Did you catch that -- 'spider silk'? Keep watching.

We're taking the black widow gene and putting it in place of the silkworm's silk gene.

And so, when they go to make the cocoons, they read the gene, and they just make it.

And instead of making regular silk, they make spider silk.

You heard correctly.

David Brigham is producing spider silk from silkworms.

But the black widow produces a silk that is stronger and stiffer than most spiders'. Brigham implants the gene that controls the production of spider silk into the silkworm.

That's right.

They eat mulberry leaves to grow big and fat.

They spin a cocoon.

And then they start turning into a moth.

They go to pupa and they would come out as a moth.

We interrupt the process to pull all the silk off their cocoon and make yarn and fabric.

You could call it agricultural alchemy.

Since silk is a natural protein fiber, putting the spider gene into the silkworm transforms the worm into a kind of protein factory for spider silk.

The silkworm doesn't change.

But thanks to genetic engineering, it's just making a different silk.

The engineered silkworms, which we tested to see if they had the spider-silk gene, and they did, one copy.

So now we're breeding transformed silkworms together so that we have offspring that have two copies of the spider-silk gene and are full strength.

To loosen up the protein glue that's holding that fiber together is we're going to put it in hot water...

But beyond the high-tech genetics, spider-silk cocoons are still processed in essentially the same low-tech way the cocoons of silkworms have been processed for thousands of years.

So we should have loosened up the glue enough in this very hot water to be able to swirl around and find that one end that goes all the way through.

And there they are.

So we're now unreeling the silk.

The way you work it, this one thread is -- well, this is not really very... thick enough to really actually run through a textile mill.

So what you do is you put, depending on how fine a fabric you're making, 10 or 25 together to make a thicker yarn.

The cocoons, with the ends of the fibers now exposed, are brought to a textile-mill reeler.

The tiny fibers are then combined one by one by one and loaded onto the mill, where they are automatically unwound.

We're making yarn.

And so, when this runs out, what you do is just grab this and throw it under, and it automatically takes up another one.

And you just keep going till you fill the reel.

By now, you're probably asking, 'Why, exactly, make spider silk?'

Spider silk is five times tougher than Kevlar.

It has not as much strength, but it has stretch.

So it's very, very tough.

And my favorite analogy is a plate-glass window and a trampoline.

You put Nolan Ryan in front of a plate-glass window, and you're pretty safe for a while, but eventually he's going to throw a fastball hard enough it's going to break that window, and then you have no protection.

But nobody throws a fastball through a trampoline.

Kevlar, Spectra -- those are plate-glass windows.

Spider silk is the trampoline.

The military is searching for a material that is not only strong but also more elastic and lightweight.

Brigham's creation has already undergone ballistic testing.

It passed until the most extreme of tests.

They kept upping the powder charge in the bullet until they defeated it.

They wanted to know how fast a bullet could go before it came through.

The fiber could also be used in a host of medical applications, such as sutures, implant codings, or even artificial tendons.

That's because the human body doesn't reject spider silk.

I'm seeing a soldier writing me a letter saying, 'I'm home because I was wearing your spider-silk vest.'

And that's why this business is here.