Synthetic biology involves engineering tissues and living cells to behave like mechanical machines. This makes it possible to design cell-based therapies, such as ones that destroy cancer cells or encourage tissue regeneration after injury. The traditional approach to this is identifying certain proteins and exciting, or silencing, the genes that make those proteins to produce a desired action within a cell. This approach can take time (for proteins to be expressed and degrade) and cost cellular energy in the process. However, a new approach is on the horizon.
Preliminary research suggests it is possible to engineer proteins that directly produce a desired result. Protein-based devices, or nano-computing agents, respond directly to stimuli (inputs) and then produce a desired action (outputs). To create such agents, the researchers first engineered a target protein by integrating two sensor domains, aka areas that respond to stimuli. In this case, the target protein responds to light and a drug called rapamycin by adjusting its orientation, or position in space.
The engineered proteins were injected into live cells in culture. By exposing the cultured cells to the stimuli, they used equipment to measure changes in cellular orientation after cells were exposed to the sensor domains’ stimuli.
Early approaches to designing nano-computing agents required two inputs to produce one output. Now, it is possible to design them in a way to produce two possible outputs, which depend on the order the inputs are received. If rapamycin is detected first, followed by light, the cell will adopt one angle of cell orientation, but if the stimuli are received in a reverse order, then the cell adopts a different orientation angle. Though still an experimental proof-of-concept, it opens the door for the development of more complex nano-computing agents.
