Technion and MIT scientists collaborated to create cells engineered to compute sophisticated functions – sort of like “biocomputers” – by combining concepts from electrical engineering and bioengineering tools. Graduate students and researchers from Technion — Israel Institute of Technology Professor Ramez Daniel’s Laboratory for Synthetic Biology & Bioelectronics collaborated with Massachusetts Institute of Technology Professor Ron Weiss to create genetic “devices” designed to perform computations similar to artificial neural circuits. Their findings were recently published in the journal Nature Communications.
The genetic material was inserted into the bacterial cell as a plasmid, which is a relatively short DNA molecule that remains distinct from the bacteria’s “natural” genome. Plasmids are also found in nature and serve a variety of functions. The genetic sequence of the plasmid was designed by the research team to function as a simple computer, or more specifically, a simple artificial neural network. This was accomplished by having several genes on the plasmid regulate each other’s activation and deactivation in response to external stimuli.
What does it mean that a cell is a circuit? How can a computer be biological?
The ability to create and control this process opens the door to more complex programming, allowing engineered cells to perform more advanced tasks. The scientists were able to produce the required genetic modifications to the bacterial cells in a significantly reduced time and cost thanks to Artificial Intelligence algorithms.
At its most basic level, a computer consists of 0s and 1s, of switches. Operations are performed on these switches: summing them, picking the maximal or minimal value between them, etc. More advanced operations rely on the basic ones, allowing a computer to play chess or fly a rocket to the moon.
The 0/1 switches in electronic computers are known as transistors. But our cells are also computers, albeit of a different kind. There, the presence or absence of a molecule can act as a switch. Genes activate, trigger, or suppress other genes by forming, modifying, or removing molecules. Synthetic biology aims, among other things, to harness these processes, to synthesize the switches and program the genes that would allow a bacterial cell to perform complex tasks. Cells are designed to detect chemicals and produce organic molecules. The ability to “computerize” these processes within the cell could have major implications for biomanufacturing and multiple medical applications.
The Ph.D students (now doctors) Luna Rizik and Loai Danial, together with Dr. Mouna Habib, under the guidance of Prof. Ramez Daniel from the Faculty of Biomedical Engineering at the Technion, and in collaboration with Prof. Ron Weiss from the Synthetic Biology Center, MIT, were inspired by how artificial neural networks function. They created synthetic computation circuits by combining existing genetic “parts,” or engineered genes, in novel ways, and implemented concepts from neuromorphic electronics into bacterial cells. The result was the creation of bacterial cells that can be trained using artificial intelligence algorithms.
The researchers were able to create flexible bacterial cells that can be dynamically reprogrammed to report whether at least one of two test chemicals are present (that is, the cells were able to switch between performing the OR and the AND functions). Cells that can change their programming dynamically can perform a variety of operations under varying conditions. (Our cells, in fact, do this naturally.)
The ability to create and control this process opens the door to more complex programming, allowing engineered cells to perform more advanced tasks. The scientists were able to produce the required genetic modifications to the bacterial cells in a significantly reduced time and cost thanks to Artificial Intelligence algorithms.
Further, the researchers took advantage of another natural property of living cells: their ability to respond to gradients. Using artificial intelligence algorithms, the researchers were able to harness this natural ability to create an analog-to-digital converter – a cell that can report whether the concentration of a specific molecule is “low,” “medium,” or “high.” A sensor like this could be used to deliver the correct dosage of medications, such as cancer immunotherapy and diabetes medications.
