The Global Demand for Spider Silk: Limited Availability and High Necessity
Spider silk possesses incredible properties that make it highly desirable for various applications. It has immense strength, elasticity, and flexibility exceeding steel and Kevlar. Orb weaver spiders can spin massive strong webs up to 1.5 meters wide that can trap birds. If harnessed at scale, spider silk could transform fields like medicine, defense, textiles and aerospace.
However, spiders are nearly impossible to farm at a large scale due to their volatile nature. They frequently attack and eat each other when kept together, as per spider silk expert Aarathi Prasad. This limitation has stymied utilizing spider silk through history despite its virtues. But now scientists aim to produce it without relying on spiders.
Recently, researchers in China modified silkworms' DNA using CRISPR gene editing to generate spider silk. The resulting silk had strength and elasticity approximating natural spider silk. This was a marked improvement over past approaches.
For instance, scientists at Utah State University earlier tried extracting spider silk protein from the milk of genetically engineered goats. But the silk fibers were weak. The goats now live on a university farm.
Previous artificial spider silk made in labs also lacked the protective glycoprotein coating spiders apply on their webs. Silkworms have an innate gland for secreting such coating, giving them an advantage.
However, Prasad notes even silkworm spider silk can't perfectly replicate natural spider silk. In spiders, silk starts liquid before solidifying into threads. We don't fully understand this natural protein folding process that imparts strength. So silkworm silk will always be part spider.
Donghua University is working to get closer by tweaking the silkworm silk's molecular structure for more strength and elasticity. They highlight an existing robust silk supply chain for silkworms that allows scalability.
The ability to produce spider silk without spiders has exciting potential if the properties can be fine-tuned. The materials could replace plastics in some single-use products, given spider silk is biodegradable. Spider silk is also hypoallergenic, meaning medical devices and sutures made from it would not cause reactions.
Spider silk could have applications in bulletproof vests, parachute cords, artificial tendons, and even space suits owing to its durability and lightness. It could reinforce airplane panels and suspensions bridges. The biocompatibility opens up possibilities in tissue engineering as well.
However, scaling up artificial spider silk does raise ecological concerns. Introducing genetically engineered silkworms or goats in the wild could impact natural populations and ecosystems. Tight regulation around their use in closed facilities would be necessary.
There are also ethical dilemmas regarding animal gene editing that require careful consideration. While spider silk production has benefits, it should not come at the cost of animal welfare or conservation. Striking the right balance will be key.
The field does show how biotechnology can provide solutions where nature poses challenges. But replicating the complex marvel of evolution requires nuance. Artificial spider silk may find uses where natural silk isn't viable, but it seems unlikely to completely replace real spider silk. There are limits to bioengineering the intricate biological processes still being unravelled.