If you live in a house, one of the most amazing materials known to humans is likely languishing in a dark corner of your basement. Spider webs, and especially spider draglines, are made from silk threads extruded by arachnids that can be several times tougher than Kevlar and stronger than steel by weight, but also extremely stretchy. Spider silk also has anti-bacterial properties, which may have led Greek and Roman soldiers to use it as wound dressing. Pictured above: Bundling several silk threads together can yield tough fibers of many shapes that are as strong as the tendons of mammals. (All image credit: Spiber Technologies)
Scientists have since proven that harvesting spider silk proteins from goat’s milk works. But a new crop of companies working to commercialize synthetic spider silk, such as Sweden’s Spiber Technologies, are moving beyond “spider goats.” Researchers can whip a solution with Spiber spider silk, just like milk, and make a fluffy foam. The foam remains solid even when immersed in solvents or sterilized with heat.
The Stockholm-based biomaterials company is using genetically engineered bacteria and GE protein purification technology to produce large quantities of the spidroin proteins found in dragline silk, and then customize them for a variety of specific purposes.“Man-made spider silk can be adjusted to contain specific parts that bind to cells and promote wound healing, thereby enabling use within fields of tissue engineering, diagnostics and cell culture,” says Kristina Martinell, production director at Spiber Technologies AB. “In short, it’s a tailor made biomaterial.”
For the most part, the company’s challenges in bringing new products to the medical world aren’t so different from the ones faced by pharmaceutical companies, Martinell says. But one specific technical difficulty has been learning to work with the stickiness of spider silk protein. “This protein, in its nature is a bit sticky,” she explains. “It has to be treated very carefully according to a specific method.”
Spiber can now manufacture spider silk fiber, film, foam and even mesh. The company says that the material is as strong as mammalian tendons and remains stable at boiling temperatures of up to 267 degrees Celsius (512 Fahrenheit). As a result, the range of potential products is huge. The company is working to apply spider silk in several medical fields, including cardiology, heart tissue regeneration, bone reconstruction, skin cell growth and vaccines. Pictured above: A drop of liquid containing Spiber protein solidifies into a transparent layer on the surface of plastic or glass labware. The resulting film can be peeled off as a sheet.
Who’s to say that a certain superhero won’t be real one day.