Jen Keane’s claim to fame is that she grew a shoe using bacteria, coaxing the microbes to deposit their nanocellulosic materials in the shape of a sneaker. But she’s kind of over that.

“I feel like that sort of misses the point,” she told TechCrunch. “The fiber produced by bacteria — like, that’s not a new thing.”

That’s not to say her new startup doesn’t use those same fibers — it does — but it takes a different tack, one that’s more similar to the way fabric is made and used today.

Her startup, Modern Synthesis, still uses bacteria to grow nanocellulose fibers, but then it harvests and processes them to create a range of different materials. The new approach is more like weaving cotton into denim for jeans. Her sneaker experiment, on the other hand, was a bit like persuading a cotton plant to deposit its fibers into the shape of a pair of pants. Cool, but not as easily scalable.

Modern Synthesis’s fibers can be manipulated in ways that simple plant fibers cannot. They can be spread into a thin, wind-resistant film or textured to mimic high-quality leather, said Keane, Modern Synthesis’s CEO. In that way, they’re more like synthetic materials like polyester and polyurethane.

The difference, though, is that Modern Synthesis’s nanocellulose materials are ultimately biodegradable. 

“You want your materials to last a lifetime or maybe two, like 100 years. You don’t want them sticking around for thousands, which is what most of the synthetic materials will do,” Keane said.

Because the basic building block of the startup’s textiles is cellulose, what’s left after they’ve decomposed is similar to what’s found on a forest floor. “It should behave similarly to other cellulosic materials,” she said. “Cotton’s a great example of that.”

One of the breakthroughs that encouraged Keane to found Modern Synthesis with Ben Reeve, the company’s chief technology officer, was the ability to create materials only using nanocellulose. Other biomaterials can mimic leather, for example, but some synthetic materials might need to be added to the mix to pull it off successfully, she said. 

Modern Synthesis buys its nanocellulose from existing producers, which already make the stuff in large quantities for a range of applications, from food additives to medical implants. The startup then processes the nanocellulose to create different materials. In 2023, for example, it made an artificial leather for Danish fashion brand Ganni, which used it to make a handbag that contained no petrochemicals.

Keane said the company is working to quintuple production at its pilot plant. Modern Synthesis recently closed a $5.5 million funding round, the company exclusively told TechCrunch. The round was led by Extantia Capital with participation from Artesian and Collaborative Fund. 

Though sneakers, clothing, and handbags are likely applications for Modern Synthesis’s materials, Keane is also looking into more sci-fi uses like smart textiles with embedded electronics and more prosaic ones like car dashboards.

“Cellulosic materials don’t melt like synthetics do,” she said. “If you think about car dashboards, how it starts to melt when you sit in the sun too long. Our materials won’t do that.”