“True circularity has to start with raw materials,” says Peña. “We talk about circularity across many industries, but for textiles, we must address what we’re using at the source.”
Engineered from recombinant DNA, SELPs are copycat proteins inspired by silk and elastin that can be customized for qualities like tensile strength, dye affinity, and elasticity. Silk’s amino acid sequences—like glycine-alanine and glycine-serine—give fibers strength, while elastin’s molecular structure adds stretchiness. Combine these molecules like Lego blocks, and voilà!—at least theoretically, you have the ideal flexible fiber.
An early-stage startup, Good Fibes creates its elastics with proteins from E. coli, a common bacterium. The process involves transforming the proteins into a gel-like material, which can then be made into fibers through wet-spinning. These fibers are then processed into nonwoven textiles or threads and yarns to make woven fabrics.
Scaling, however, remains a challenge: To produce a single swatch of test fabric, Blake says, she needs at least one kilogram (approximately two pounds) of microbial material. The fibers must also be stretchy, durable, and resistant to moisture in all the right proportions. “We’re still solving these issues using various chemical additions,” she says. For that reason, she’s also experimenting with plant-based proteins like wheat gluten, which she says is available in larger quantities than bacteria.
Timothy McGee, a biomaterials expert at the research lab Speculative Technologies, says manufacturing is the biggest hurdle for biotextile startups. “Many labs and startups around the world successfully create recombinant proteins with amazing qualities, but they often struggle to turn those proteins into usable fibers,” he says.
