Scientists from designed an implant comprising of a pack of multi-functional ultra-thin polymer fibers.
Amongst other things, implants of brain are able to stimulate specific neurons, as well as deliver medication in specific regions. The experimental novel implant can overcome the frequent limitation of the others, through transforming from hard states to soft. Existing implants include devices including electrodes that are typically legitimately stiff. However, brain tissue in which these electrodes are implanted, is extremely soft. Hence, the immune system of body tends to recognize implants as some foreign objects, developing a scar tissue layer around them. As time passes, this layer grows thick enough so that it avoids the implants to function properly.
Looking for an alternative, the scientists from the Korea Advanced Institute of Science and Technology (KAIST) designed an implant comprising of a pack of multi-functional ultra-thin polymer fibers, surrounded by and embedded in a hydrogel -polyacrylamide-alginate. This fiber bundle includes an optical waveguide to stimulate neurons through light exposure, 3 microelectrodes to monitor neuronal activity, along with 3 microfluidic channels to deliver liquid medication.
Since this hydrogel is stiff in the initial dry form, it could be inserted relatively easily within brain tissue without using any supportive devices for guiding. However, once implanted, they absorb the body fluid, becoming very pliable and soft – very much like tissue surrounding it. It means that it is perceived less likely as any foreign object. After testing upon lab mice, this implant was capable of detecting neural signals for around 6 months, which reportedly is "way beyond what was recorded previously." Additionally the researchers noted a remarkable reduction within responses of foreign body, in comparison with conventional implants. The paper on this research was published recently in the Nature Communications journal. And it isn't the only time it has been heard regarding hydrogel being utilized for implants that are brain-friendlier.