Scientists create platform for devices that wrap around nerve fibers
Polymer sheets controlled with light may offer way of aiding myelin sheath
A new technology is designed to be a “wearable” device for neurons, wrapping around individual nerve fibers with a goal of achieving new ways to study and treat neurological diseases like multiple sclerosis (MS).
Still in early testing stages and needing further refinement, the technology was developed by scientists at Massachusetts Institute of Technology (MIT).
“The concept and platform technology we introduce here is like a founding stone that brings about immense possibilities for future research,” Deblina Sarkar, PhD, an assistant professor at MIT and the study’s lead investigator, said in a university news story.
The technology is described in the paper, “Light-induced rolling of azobenzene polymer thin films for wrapping subcellular neuronal structures,” published in Communications Chemistry.
A possibility of moving wearable sensors to subcellular level
Nerve cells use wire-like projections called axons and dendrites to connect with each other and send electrical signals throughout the body, ultimately controlling everything from movement to cognition and emotions.
MS is characterized by damage to the myelin sheath that wraps around those fibers. Myelin is essential for the rapid and efficient transmission of nerve signals, so its deterioration disrupts nerve cell communication and causes a wide range of neurological disease symptoms.
Over the last decade or two, wearable technologies have advanced by leaps and bounds. Sensors worn on the wrist like a watch can be used to track everything from how much a person walks to how fast their hearts beat and how well they sleep.
In theory, it might be possible to take the idea of wearable sensors down to the subcellular scale. The basic idea would be to create sensors that can wrap around individual nerve fibers, detecting electrical signals or even modulating nerve activity.
A main obstacle toward developing this type of technology is that nerve fibers are tiny, twisty, curvy structures. Until now there hasn’t been a way to create technology that can wrap around the fibers tightly enough to be useful as sensors, but not so tightly as to cause harm.
“Due to their high curvature, axons and dendrites are among the most difficult neuronal structures to conformally enwrap with a synthetic platform,” the scientists wrote.
Technology said to finely control how polymers wrap around nerve fibers
MIT researchers report having taken a major step in this direction.
The team devised a system using sheets of repetitive molecules, called polymers, that can be controlled with light. Basically, the flat polymers are injected next to nerve fibers, then light is used to cause the polymers to roll and curl so that they wrap snugly around the fibers.
“It is possible to very finely control the diameter of the rolling. You can stop if when you reach a particular dimension you want by tuning the light energy accordingly,” Sarkar said.
So far, the researchers have tested this platform using cell models in a dish in lab settings. Still, they expect that the technology could be expanded to allow for use in living organisms, pending further tests of efficacy and safety.
“This work is an exciting step toward new symbiotic neural interfaces acting at the level of the individual axons,” said Flavia Vitale, PhD, a professor at the University of Pennsylvania who was not directly involved with the study.
Vitale added that this technology “could become a versatile platform to sense and deliver different types of signals (i.e., electrical, optical, thermal, etc.) to neurons and other types of cells in a minimally or noninvasive manner.”
Future work, the scientists noted, should include “integrating and testing” materials relevant to work in neurological diseases, and evaluating the technology in living organisms.
“Not only could these interfaces provide modulation, sensing, and drug delivery, but they could also be engineered to electrically and periodically insulate the axons … to obtain a synthetic myelin-like layer to study neurodegeneration dynamics and potential neuroprotection in demyelinating diseases,” the team concluded.
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