Spider silk is being harnessed or a range of medical and technological applications. The material is pound-for-pound stronger than steel.
Professor Fritz Vollrath has worked with spiders for more than 40 years and has pioneered the use of their uniquely strong silk to address a variety of medical problems. Here, he looks at one of the Golden Orb Weaver spiders he keeps in his greenhouse at Oxford University.
Vollrath's Silk Group at Oxford University extracts silk from anesthetized spiders by pinning them and using an automated reel, which can produce over 20 meters of silk per day.
Vollrath has made breakthroughs in the study of spider silk at the nanoscale. He discovered a unique molecular alignment of the proteins within, which gives the silk its strength, and is remarkably resilient to stress and deformation.
Vollrath took commissions from the U.S. military to study how drugs, including LSD, affected a spiders' web building. Pictured, three seperate images illustrating experiments of spiders making webs under the influence of the drugs Benzedrine (L), Caffine (C) and Marijuana, (R).
The Golden Orb Weaver produces seven types of silk for its web. The strongest is dragline silk, which Vollrath's group uses as a model for a new type of biomedical implant. Spider silk is difficult to manufacture in bulk as reeling is extremely labor intensive and spiders cannot be farmed as they are cannibals.
Silkworms have been farmed industrially for thousands of years using an established method of boiling and extrusion. Vollrath's team use a process of electro-spinning to engineer the molecular structure of a species of silkworm to match that of a spider's, giving the silk the same strength and quality. They call the resulting material Spidrex.
The Silk Group is using the material to produce knee replacement implants, pictured, through spin-off company Orthox. The implants are highly biocompatible and support regeneration of cartilage. They are currently in human trials, and could be available by 2018.
Spidrex 'scaffolds' are also being applied to nerves and have been shown to support peripheral nerve regeneration (seen in green). Vollrath is also targeting the central nervous system, which could reverse the effects of severe spine injuries such as paralysis.
Silk-based medicine is now a rapidly growing field, with wound dressings, screws (pictured), sutures, and artificial organs among the applications being developed.
Vollrath has promoted the use of silk in multiple disciplines. He collaborated with leading architect Peter Rice to design buildings that draw on the structure of spider webs, such as the 'Pavilion of the Future' in Seville, Spain (pictured).