By Janet Raloff
From Chicago, at the American Chemical Society Meeting
A new controlled-release system relies on enzymes to unshackle chemicals only when and where they’re needed. Scientists at the Netherlands Organization for Applied Scientific Research in Zeist are developing what they’re calling bioswitches for a number of applications, such as a germ-killing plastic wrap for meats.
The researchers encapsulated lysozyme—a natural antibiotic—within a cage of chemically linked starch molecules and seeded the complexes onto the wrap’s surface. Any bacteria contaminating a piece of meat would view the starch as a snack, explains project manager Hans Boumans, a biochemist. Once the microbe starts feasting on the starch cage, it opens holes and releases the killer lysozymes. “It’s like a Trojan horse,” says Boumans.