More Reliable Biological Circuits

synthetic biological circuits more precise

Image credit: Christine Daniloff/MIT (yeast cell images from National Institutes of Health)

Researchers have made progressed in the field of biological circuits. A new device have improved predictability of synthetic biological circuits to almost reach the level of their electronic counterparts.

Biological circuits are devices of biology design that activates in response to a signal inside the body. What this signal is varies with what you are trying to achieve. You could build a synthetic biological device that responds to high blood sugar by activating a gene product like insulin, as an example. The problem with biological circuits compared to their electronic counterparts is that signals in biological systems aren’t binary. Since there’s no specific on or off trigger and more of a sliding scale signal, the systems are unprecise. Researchers at MIT think they have solved the problem of synthetic circuits not consistently producing an output to a given signal.

Load Drivers make Biological circuits are more predictable

The findings of the MIT researchers engineering improvement is published in Nature Biotechnology.

Biological circuits have many potential areas of use. One such area is biosensing, detecting a specific molecules in the environment and reacting to that signal. Co-authors of the paper Del Vecchio and Weiss explain that one such example could be detection of cancer cells in the body that triggers the releases of specific molecules to kill them. This type of biological circuit could be highly useful in medical science and health care in general. But the example highlights the need for precise control, you don’t want the biological circuits to release harmful molecule near normal healthy cells.

Predicting this response in synthetic biology is much harder since systems aren’t connected by wires where information always gets where its going. The signals in biological circuits travels by molecules suspended in fluid making it harder to reach their intended target. Chemical interactions in biology systems are simply more likely to fail.

MIT researchers think they have solved this uncertainty issue by inserting a load driver into the circuits. The load driver provides a buffer between the signal and the output preventing the effect of the signal from backing-up the system causing delays in output. If you have a glucose sensing system in the blood stream, you want an insulin response at the moment it detects a rise in blood sugar not one hour later.

Researchers think that these load drivers can make biological circuits more design versatile and more predictable. Although real world applications are years away researchers tease that the advance could, as an example, result in a biological circuit that constantly measures blood sugar levels in diabetes patients and release insulin into the blood stream when it’s needed.

Design principles of these circuits is to produce the effect you’re looking for every time you get a signal. This advance show that a first step to a more reliable biological circuits are here and it will be exciting to see where this leads in the future.