The line between artificial and living materials is becoming increasingly blurred thanks to a new breakthrough in synthetic biology. Researchers at the University of North Carolina at Chapel Hill have created synthetic cells that behave like live cells, but with a twist. They can be reprogrammed to perform multiple functions and operate in conditions that would be prohibitive for natural cells. The secret? Self-assembling synthetic cytoskeletons, built with DNA and proteins.
DNA as a building material
In natural cells, the cytoskeleton provides structure and stability, protecting other cellular components. Depending on the cell type, this cytoskeleton can be more or less flexible and respond in different ways to the surrounding environment, giving cells their specialized abilities.
But DNA is not normally part of the cytoskeleton. The researchers had to reprogram DNA sequences to act as an architectural material, binding peptides together. “We reprogrammed DNA sequences to act as architectural material, binding peptides together,” he explains Ronit Freeman, lead author of the study that I link to you here.
Once this programmed material was placed in a drop of water, the structures took shape.
Multifunctional synthetic cells
The ability to program DNA to self-assemble in different ways, as mentioned, has allowed researchers to create synthetic cells with different functions. And they are not locked into one purpose: by changing the temperature of the solution, different configurations can be triggered. By combining different peptides or DNA sequences, programmable tissues can be obtained on a larger scale, the team says.
While not as complex as live cells, these synthetic cells are easier to manipulate and can function in conditions that natural cells could not withstand.
The synthetic cells were stable even at 50°C, opening up the possibility of producing cells with extraordinary capabilities in environments normally unsuitable for human life.
Ronit Freeman, University of North Carolina
Towards new frontiers of medicine
Integrated with other synthetic cell technologies, these programmable cells could find applications in a variety of fields, from regenerative medicine to drug delivery systems, through diagnostic tools.
Imagine, for example, synthetic cells designed to repair damaged tissue, capable of adapting to local conditions and performing multiple tasks, from stimulating cell growth to suppressing inflammation. Or again, artificial cells loaded with drugs, capable of reaching specific sites in the body and releasing their "cargo" in a controlled and targeted way.
Again: synthetic cell factories capable of producing customized chemical compounds or materials, or artificial cells designed to purify water or air of contaminants. Synthetic fabrics capable of self-repairing or adapting to external stimuli. The list could go on and on.
Synthetic cells, a step forward in biology
This study represents a significant breakthrough in the field of synthetic biology, a discipline that aims to create artificial biological systems with new or improved capabilities compared to natural ones.
Until now, much of the effort in this field has focused on creating synthetic genetic circuits inside living cells, reprogramming their DNA to perform desired functions. But Freeman and colleagues' approach goes further, creating entirely synthetic cells from scratch, with self-assembling cytoskeletons that can be programmed at will.
Of course, we are still far from these futuristic scenarios. The synthetic cells created by Freeman and colleagues are still relatively simple compared to their natural counterparts, and much work remains to be done to increase their complexity and capabilities. This research, however, lays the foundations for a future in which the boundary between organic and synthetic becomes increasingly blurred. A future in which synthetic cells work alongside or even surpass natural ones, paving the way for technologies and applications that were previously unthinkable.
