Narrow archways and hiking paths share a common danger and, when abandoned long enough, will elicit screams from bumbling pedestrians. The lucky ones may notice a glint of light and save themselves the trouble. But for those unlucky enough to walk through unaware, there is nothing worse than a face full of spider web.

The qualities that make spider silk so unpleasant to run into also qualify it as an engineering marvel. Its enormous elastic capabilities, shared with a resistance to tearing under strain, give it high marks in the metric of “toughness.” It is unique from caterpillar silk, which merely coats the larvae for protection during metamorphosis. The spider’s predatory web is high performing enough to at times catch small birds. Now, scientists are taking a second look at this silk, evaluating its potential for synthetic biology and material design.

Spider silk is made of repeated protein chains called spidroins. There is great mechanistic diversity across the 50,000 spider species, with many recorded varying motifs. Darwin’s bark spider, for instance, builds structural drag-lines that span rivers and can stretch up to about 50% while maintaining a tensile force akin to that of steel wire. These spiders can vary the amino acid make-up of their spidroins to suit different silk types. Triangle weaver spiders, for instance, build particularly elastic webs that they pull back to snap onto prey. Protein screenings of this spider show an abnormal richness in proline, a nitrogen-containing amino acid common in drag-line webbing.

Beyond impressive baseline mechanics, spider silk has adapted to respond to the elements.

Interestingly, their toughness is improved when wet. Spider webs undergo a supercontraction when coated with water, compressing the material into a shrunken web. Rain and humidity cause water molecules to disrupt bonds between the spidroin proteins, converting their rigid attachment into a more rubbery state. The web, in turn, is more durable in rain.

Glittering in the light, spiders face another problem. Researchers from Malaysia determined that spider silk degrades quickly under UV radiation, which causes main-chain protein damages. In lab conditions, expandability dropped by half and toughness by a fifth after just 30 minutes of UV exposure. While nocturnal spiders suffer these hindered mechanics, day-roaming arachnids appear to have adapted to the light. These species, including the golden orb-web spider, create silk impervious to such UV degradation, a mechanism which remains a mystery.

Understanding the molecular underpinnings of webbing is more of a practical move rather than merely fulfilling a curiosity. Because of spiders’ predatory nature, they cannot be simply farmed for their silk the way caterpillars are. While caterpillars will form cocoons regardless of crowded conditions, spiders turn territorial and cannibalistic in close quarters. Further uncovering the molecular engineering of spidroins is thus necessary to open doors for various human applications.

Researchers from the National Institute of Science and Technology in Brazil and from the University of Utah studied the applications of using synthetically developed spidroin proteins. Of the various opportunities, they propose creating extracellular matrixes to scaffold cell growth. There is also potential to take advantage of the silk’s water-resisting character to improve drug delivery systems, preventing “burst release” issues common in water-soluble delivery methods.

To manifest these applications, the team used an awareness of the structure and properties of spidroins to develop recombinant spider silk proteins through modified hosts. These proteins are created by genetically modifying alternative host organisms including bacteria, yeast, cell lines, or even plants or animals.

With all of this in mind, hikers caught in a spider’s trappings may find some solace: How lucky they are to so closely witness this bioengineering marvel. The elastic threads people madly swipe away may just inspire life saving technology.