The Race to Put Silk in Almost Everything
Johns injects less than a tenth of a teaspoon of the mixture of silk and hyaluronic acid through a special catheter wired with his endoscope. He keeps his patients awake by injections, putting them in position in that feather chair. The procedure takes about two minutes. Like other vocal injections, the results appear immediately. The gel tightens the tissue, strengthening the anatomy until the entire tissue can regrow and recover. “These people are very happy,” Johns says. “These are a kind of life-changing procedures for them.”
The study with Johns will last about two years, but SilkVoice is already authorized for human use. So far, says Hoang-Lindsay, most of the 40 people who received the injections have maintained their improvements.
Meanwhile, a Boston base a startup called Mori has quietly marketed silk as a way to protect food.
As a materials engineering postdoc in Omenetto’s lab in 2014, Benedetto Marelli accidentally invented a solution for food jets. “We had a cooking contest in the lab where we had cooking with silk,” says Marelli. He planned to immerse the strawberries in regenerated silk from silkworms, as if it were a light melt. The result was subdued. He lost the contest, threw the strawberries aside, and forgot about them. A week later, half of them were completely withered. The others always seemed fresh. The silk protein had created a thin layer that matched the surface of the fruit. The water was running out, and oxygen was out, Marelli says. Bacteria digest the silk too slowly to contaminate the products buried underneath.
With this idea in mind, Marelli launched Cambridge Crops, now known as Mori, to address food waste and insecurity by posing dangers to make it last longer. “I like to use the example of a zucchini slice,” says Mori CEO and co-founder Adam Behrens. Unlike wax, Mori coating can stick to water-repellent and porous surfaces, such as the outside and inside of a pumpkin.
The company integrates spray paint — or dip-coat, like Marelli’s happy accident — directly into food washing and packaging processes. Leafy greens and cherries, for example, often go through cleaning cycles before reaching the food. (Marelli, now an associate professor of civil and environmental engineering, remains a consultant and shareholder but has moved away from his operations.)
Last year, a panel of allergists, toxicologists and nutritionists designated the coating as “generally recognized as safe,” meaning that the public can buy and eat it. Mori already has pilots running farms and food companies in the United States, and large-scale manufacturing is expected to begin later this year.
These startups are far from the only ones that focus on silkworm silk. Vaxess, another spinoff of Tufts, makes silk microneedle patches available to dispense vaccines. Their patch preserves sensitive vaccine antigens in the small tips of silk microneedles, and can work with conventional vaccines already approved by the FDA. The goal is to make vaccines stable across the board that are easier to spread, according to Kluge. The Gates Foundation has supported some of its trials on animals, and Kluge says Phase 1 human safety studies should begin early next year. (Omenetto and Kaplan are scientific co-founders in Vaxess, Mori and Sofregen.)
While cultivating silkworms can spew nine Eiffel towers worth of cocoons each year, scientists have not given up trying to convince the same from other creatures. “Spider silk is stronger than silkworm silk, and it’s more elastic,” says Lewis, a former biologist at the University of Wyoming who has taken over the BioSteel goat herd. (He is now in Utah State).
But spider farming is still out of the question. So Lewis spent decades looking for a solution. In the late 1980s, he consulted for a company that figured out a way to assemble repeated long chains of amino acids – new proteins. They asked him if he could use that to make spider silk. “The problem was that there was literally no protein information about silkworms,” Lewis says.