It’s no secret that spider silk is incredibly strong; it’s the premise behind the superhero Spiderman and has been a topic of research for quite some time. Companies have been working to synthesize spider silk in commercial quantities, however, despite the fact that the silk producing gene was cloned in 1990, the industry has faced several obstacles in both its development and implementation.
Since spiders are territorial and cannibalistic, they can’t be raised in concentrated colonies for silk production. This has led scientists to implant the spider silk gene into other organisms, such as yeast, E. Coli bacteria, goats and, most obviously, silkworms. Because Forty percent of the silk worms’ weight is devoted to the silk glands, they are naturally suited to produce genetically engineered spider silk. The reason this endeavor has been so complicated is because the silk that a spider uses to make its web is actually the combination of six different kinds of strands, spun together to give the web its strength, flexibility, and stick.
Markus Buehler, head of the Department of Civil and Environmental Engineering at MIT said, “It is possible to make silk proteins synthetically, but it is very hard to assemble the individual proteins into a fiber or other material forms… The spider has a complex spinning duct in which silk proteins are exposed to physical forces, chemical gradients, the combination of which generates the assembly of molecules that leads to silk fibers.” The extraordinary tensile strength of spider silk actually comes from the fact that each strand, already 1,000 times thinner than a human hair, is composed of thousands of nanostrands.
This complex structure means that it could revolutionize textiles like rope, seatbelts, or parachutes, as well as the potential of a life-saving ballistic resistant material, which is lighter, thinner, more flexible, and tougher than steel. Spider silk isn’t only valued for its strength, however. Because the proteins that make up the silk consist of a highly repetitive sequence of small amino acids, they are not targeted by the human immune system and deflect bacteria better than Teflon or stainless steel.
Following this line of thought, using spider silk proteins to coat implants would make them less likely to be rejected by the human body. As published by Prof. Dr. Thomas Scheibel and coworkers, “a coating of recombinant spider silk proteins onto a silicone implant prevents post-operative inflammatory and fibrotic complications.” Since it is biocompatible and suppresses inflammation, it could also be revolutionary for adhesives and bandages, and perhaps even sutures or replacement tissue.