Technology that restores tactile sensation in damaged nerve regions.
There are injuries, such as accidentally cutting a finger with a knife, that can result in loss of tactile sensation due to nerve damage, and although there are some solutions to restore tactile sensation, such as surgical reconstruction of the nerve through nerve autografts, among others, its success rate is low.
In the search for better solutions, researchers focused on the development of a flexible, durable and small device, made of a biocompatible material, to avoid damage to the tissue surrounding the implant and with a wide range of sensitivity, corresponding to normal human pressure perception, as well as simple in design and implantation.
The technology on which the research focused was the triboelectric nanogenerator (TENG), which converts mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction (using the triboelectric effect). The device is implanted under the skin (for example, of a desensitized finger), and when tactile pressure is applied to the device, an electrical signal is generated and transmitted via insulated wires to a stimulation electrode wrapped around the nearest undamaged nerve fiber, which transduces a tactile sensation signal to the central nervous system, that is, transforms touch into voltage that is transduced to healthy sensory nerves to excite peripheral neurons proportional to the pressure applied to the device.
Credits: Shlomy et al. (2021) (ACS Nano) CC BY 4.0.
The device is composed of positive and negative dielectric materials placed on top of a metal electrode. Polydimethylsiloxane (PDMS) as the negatively charged dielectric material and cellulose acetate butyrate (CAB) as the positively charged layer. For the metal they used a thin layer of gold (Au), which was evaporated on kapton (Kapton) to achieve stability. Notably, the device does not require an external power source, such as batteries.
Credits: Shlomy et al. (2021) (ACS Nano) CC BY 4.0.
To test and validate the device, they used a rat model, performed a preliminary dissection to map the sensory nervous system of the rat's hind paw. The rats were divided into three groups: "control", in which no procedure was performed; "amputee", in which a segment of the left distal tibial nerve was removed; and "device", in which a segment of the left distal tibial nerve was removed and a device was implanted in the left hindfoot and connected with electrodes to the terminal part of the remaining portion of the left distal tibial nerve.
Credits: Shlomy et al. (2021) (ACS Nano) CC BY 4.0.
After the rats recuperated from surgery, their movement was monitored and the sensation of the rats was measured by applying an increasing force to the rat's paw from below (upon sensing the force, the rat lifted its paw). The rats in the "device" group responded to a much lower amount of force compared to the "amputee" group. The amount of force required for the "control" group was similar to that of the "device" group.
Overall, the research demonstrated the in vivo functionality of a device to restore tactile sensation.
Hello @capp
First time reading a post of yours, interesting topic. I think that if advanced further it could be a solution for many problems of neurological origin.
I hope so, countless people annually suffer serious accidents that condemns them, if somehow science can collaborate, it is a breakthrough.
Hi @josevas217. Somewhere I read that the surgeon Arami spoke with biomedical engineer Maoz about the difficulties he experiences in treating people who have lost tactile sensation in an organ as a result of injury, and from the conversation it emerged that the two decided to tackle the challenge to find a solution. It is a start but many factors were taken into account for further research.