'Endless possibilities': On a mission to create the materials that don't exist

Synthetic chemists are moving forward with a breakthrough method known as skeletal editing, which could pave the way for revolutionary advances in medicine and sustainable plastics

- Ned Carter Miles

Ask Mark Levin what excites him about his work, and the associate professor of chemistry at the University of Chicago could double as a poet.

"We're one of the only fields of science that at its core is about making things that have never existed anywhere else in the universe, and would never have existed if we didn't intervene," he says. "We get to manipulate matter at the atomic level to shape it to whatever purpose we can think of."

Some of those things that would never have existed are of immense value to humanity. From synthetic dyes to celluloid, materials to medicines, synthetic chemistry has made our world a richer place, and helped us live longer to enjoy it.

With effort, chemists can synthesise almost any molecule imaginable, but methods are limited, relying on the molecular building blocks available and potentially requiring many steps. "The approach that has been adopted is to add other chemical groups to the already existing molecule, which changes it only on its periphery," says Prof Richmond Sarpong, at the University of California, Berkeley.

When it comes to altering a molecule more fundamentally, Levin likens those atoms and bonds to the connectors and rods in a child's construction set: "It's very obvious when you're looking at the toy that the best way to change it would be to pull out the part you don't want and put the new one in," he says. "It has always bothered me that that's not something we have the capacity to do chemically."

That is, not until now. Inspired in part by the revolutionary genome-editing technology Crispr-Cas9, Levin and Sarpong are among a handful of chemists developing methods to insert, delete and swap individual atoms within molecules. They call it "skeletal editing" and they hope it will change their field - and our world by harnessing chemical reagents, catalysts or light, to perform edits quintillions of times.