Three kinds of nerve conduits to repair the injured peripheral nerve. (a) Nerve conduit with microchannels. (b) Nerve conduit with a shape of thin slice. (c) Nerve conduit with concentric tubes.
There has been considerable work done by investigators around the world on overcoming severe nerve damage by bypassing the signals around the injury, as well as using stem cells to regrow the patient’s own nerves. Scientists at Tsinghua Univeristy in China have taken a different approach and used a liquid metal as an electrical conduit to bridge a gap in broken sciatic nerves.
The experimental diagram for the overall system. (a) The experimental setup of measuring the electroneurographic signals. (b) The schematic diagram of the transected sciatic nerve reconnected by liquid metal and Riger’s Solution, respectively. To view it clearly, a little red ink was added into the Riger’s Solution.
The used the GaInSn alloy (67% gallium, 20.5% indium, and 12.5% selenium by volume), that stays liquid at body temperature, to connect sciatic nerves to detached muscles taken from bullfrogs. They measured the electric signals before the nerves were severed and then after being connected by the liquid metal or the control Riger solution, a salty, body fluid-mimicking substance. They showed that the liquid metal provided electrical connectivity “close to that from the intact sciatic nerve,” according to the study, and that the approach has potential to become a way of treating a variety of debilitating conditions.
From the study abstract in arXiv:
The control experiments through replacement of GaInSn with the conventionally used Riger Solution revealed that Riger Solution could not be competitive with the liquid metal in the performance as functional recovery channel. In addition, through evaluation of the basic electrical property, the material GaInSn works more suitable for the conduction of the weak electroneurographic signal as its impedance was several orders lower than that of the well-known Riger Solution. Further, the visibility under the plain radiograph of such material revealed the high convenience in performing secondary surgery.
Study in arXiv: Liquid Metal as Connecting or Functional Recovery Channel for the Transected Sciatic Nerve…
(hat tip: MIT Tech Review)
