DOE Renews Hammer and Lee’s Grant to Study Synthetic Cells

Daniel Hammer, Alfred G. and Meta A. Ennis Professor of Bioengineering and Chemical and Biomolecular Engineering, and Daeyeon Lee, Associate Professor of Chemical and Biomolecular Engineering, had their grant renewed by the Department of Energy’s Biomolecular Materials program to determine how to build communication machinery into synthetic materials and ultimately engineer synthetic cells.

The project, titled “Development of Smart, Responsive Communicating and Motile Microcapsules,” is inspired by theoretical research done by the University of Pittsburgh’s Anna Balazs, who developed particles that communicate with one another to induce “collective motion” – an array of particles move in a concerted way by communicating with one another. Balazs’s theorized that such a system could be realized by using two kinds of particles: senders and receivers. The receiver can either be attracted to or repelled by a sender’s secretion. If the receiver is attracted, it moves toward the sender. If the receiver is repulsed, it moves away from the sender and pulls the sender, causing it to chase the receiver.

These reactions are examples of autonomous movement, which is ubiquitously observed in living things, such as flocks of birds. Hammer and Lee aim to capture the behavior of living things in a synthetic cell – also known as protocell. Their work involves putting uniform-sized capsules on an array and then using an enzyme cascade to get a sender particle to secrete signaling particles and have receivers respond.

Synthetic cells can serve as means of converting energy, as applied by optical illumination or by enzyme-catalyzed biochemical reaction, into coordinated motion of particles and fluids. They can also be used to develop environmentally sensitive materials that display self-healing or large-scale coordinated function.  An application of such materials would be to serve as means of converting energy, as applied by optical illumination or by enzyme-catalyzed biochemical reaction, into coordinated motion of particles and fluids. Another would be to develop environmentally sensitive materials that display self-healing or large-scale coordinated function.