In a new paper published in Nature Chemistry, UNC-Chapel Hill researcher Ronit Freeman and her colleagues reveal the methods they took to modify DNA and proteins — critical building blocks of life — to generate cells that appear and operate like those found in the body. This breakthrough, the first in the sector, has ramifications for regenerative medicine, medication delivery systems, and diagnostic tools.
“With this discovery, we can think of engineering fabrics or tissues that can be sensitive to changes in their environment and behave in dynamic ways,” says Freeman, who works in the Applied Physical Sciences Department of the UNC College of Arts and Sciences.
Cells and tissues are composed of proteins that work together to conduct functions and produce structures. Proteins are required to construct a cell’s structure, known as the cytoskeleton. Without it, cells would be unable to operate. The cytoskeleton permits cells to change shape and respond to their surroundings.
With this discovery, we can think of engineering fabrics or tissues that can be sensitive to changes in their environment and behave in dynamic ways.
Dr. Freeman
Without using natural proteins, the Freeman Lab created cells with functional cytoskeletons that can change shape and respond to their surroundings. To accomplish this, scientists used a new programmable peptide-DNA technique that guides peptides, the building blocks of proteins, and repurposed genetic material to assemble a cytoskeleton.
“DNA does not normally appear in a cytoskeleton,” Freeman says. “We reprogrammed sequences of DNA so that it acts as an architectural material, binding the peptides together. Once this programmed material was placed in a droplet of water, the structures took shape.”
The ability to program DNA in this way means scientists can create cells to serve specific functions and even fine-tune a cell’s response to external stressors. While living cells are more complex than the synthetic ones created by the Freeman Lab, they are also more unpredictable and more susceptible to hostile environments, like severe temperatures.
“The synthetic cells were stable even at 122 degrees Fahrenheit, opening up the possibility of manufacturing cells with extraordinary capabilities in environments normally unsuitable to human life,” Freeman says.
Instead of designing materials that will last, Freeman claims that their materials are designed to accomplish a specific function before modifying to serve a new function. Their application can be tailored by including various peptide or DNA designs to instruct cells in materials such as textiles or tissues. These new materials can be used with other synthetic cell technologies, with prospective uses that could transform sectors such as biotechnology and medicine.
“This research helps us understand what makes life,” Freeman explains. “This synthetic cell technology will not just enable us to reproduce what nature does, but also make materials that surpass biology.”
