A sensor has been developed to monitor fluctuating proteins within the body in real time. This is in the form of a new implantable medical device that functions ‘like a tree branch’ to grab proteins. The device comprises strands of DNA that stick to proteins, shake them off and then grab more proteins.
To present the benefits of the device, the Northwestern University researchers used an animal study to deploy the device to accurately track biomarkers of inflammation (assessing protein biomarkers of inflammation in diabetic rats). Going forwards, the device could additionally track protein markers for other illnesses, including heart failure.
According to lead researcher Shana O. Kelley, interviewed by Lab Manager: “The device’s design is analogous to a continuous glucose monitor that sits on your arm and measures levels right beneath your skin. You can see that your glucose levels are increasing in real-time. But then maybe you take your insulin, and your glucose goes back down.”
Kelley adds: “You need to be able to measure trends in the wrong direction and trends in the right direction. It’s the same with proteins in inflammation. We need to track fluctuations in order to get a full picture of what’s happening in the body. This is a completely new capability — to be able to watch inflammation in real time. There are a huge number of applications that we are now beginning to explore.”
The nanoscale sensors are described by the researchers are resembling ‘rows of bulbous pendulums’, each comprising a double-stranded cord of DNA. One end of the DNA strand is attached to an electrode, and the other end is attached to another bit of DNA that binds to a desired protein.
When the researchers apply an alternating electric field, the pendulum-like sensors swing back and forth — flinging off proteins within a mere minute and catching others. The DNA sensors can ‘release’ their proteins after each measurement cycle, enabling continuous, real-time monitoring inside the body.
For the animal study, the researchers designed sensors to bind to two protein cytokines, which are key markers of inflammation. Then they attached the device into the skin of rats with diabetes. Because diabetes and inflammation are tightly linked, many complications associated with diabetes are caused by inflammation.
The sensors successfully measured concentration changes of both proteins within fluid. When the rats fasted or received insulin, the sensors tracked cytokine levels as they drifted down. Conversely, when researchers injected the rats with a substance that agitates the immune system, the inflammatory cytokine levels rapidly shot up.
The research has been published in the journal Science, titled “Active-reset protein sensors enable continuous in vivo monitoring of inflammation.”
