Biomaterials research watch: future silk

Long-time readers may recall my fascination with the desire to mass produce spider silk--something notoriously difficult because spiders are highly territorial and cannibalistic and cannot be housed together in the numbers needed to make this possible. For those unfamiliar, spider silk is one of the holy grails of materials research because it has a tensile strength greater than steel, the extensibility of rubber, the water uptake capability of wool, and is biodegradable.

Fibre researchers are particularly interested in its potential use in biomedicine, and since the early 2000s researchers have looked at different ways that the necessary silk proteins could be created. Cows, hamsters, transgenic goats and even bacteria have all been made to produce the proteins needed to make silk, but it has proven much more difficult to replicate a spinneret, the spider's spinning mechanism. This is further complicated by the desire to "improve" on the spinneret by making it capable of faster spinning, since the biotech industry moves faster than nature.

In 2006, engineers at MIT came closer to understanding how spiders spin silk, and today's news reports that German researchers have constructed "a device that consists of three channels etched into glass" that can control the levels of salt and proteins needed to make silk. However, the same article also quotes researchers at Oxford Biomaterials saying that "certain wild silks are stronger when you unravel them than natural spider silks" so it may be that spiders get passed over for Chinese and Indian wild silkworms.

Still, processing silk is very expensive, and it's hard to say how viable either will be for the type of mass production needed to keep American soldiers alive longer, let alone to make implantable medical textiles for the rest of us.