Few materials in nature are as strong yet also as pliant as spider silk. The versatile fiber is made from a mixture of complex proteins in the spider's silk gland and dispensed at quite a clip--an individual spider can produce up to 100 yards of silk a day--from its spinnerets. The particular arrangement of the amino acids in these proteins creates a mix of hard, crystalline regions and amorphous, elastic regions that give silk fibers their amazing tensile strength and elasticity.
These enviable features have made spider silk the frequent target of biomimetic efforts by scientists who hope to produce a synthetic version in large enough quantities for applications in industry, military technology (it's three times tougher than Kevlar), and medicine (as a super-strong, biodegradable suture material, for example). While researchers are still wrestling with this challenge, recent studies have shown that a silk-like biomaterial could be electrospun to construct scaffolds in human bodies. The nanofibers' structural resemblance to proteins like collagen and elastin found in connective tissue make silk an ideal scaffolding material for vascular grafts and bone/cartilage engineering.