Epilepsy is the most common neurological disorder that affects 50 million people worldwide. It is one of the diseases that is under-researched. Scientists from the Technical University of Denmark (DTU), the University of Copenhagen, University College London, and other institutions have developed an invasive thin-needle brain implant called microfluidic Axialtrode (mAxialtrode) that serves multiple functions, paving the way for brain development and its therapeutic practices. It has three functions: record neural activity, deliver drugs or medication, and stimulate multiple brain regions simultaneously using a single flexible fiber across different parts of the brain.
It has a light-conducting core encircled by eight tiny channels within the fiber. It is a 2.7-millimeter depth separation for drug injections that can accommodate ultra-thin metal wires for electrical activity measurement and carry medicines. This implant offers several functional sites throughout its length, enabling researchers to simultaneously target several brain layers in contrast to traditional flat-ended optical fibres that only interact with brain tissue at their tips.
The needle-thin mAxialtrode begins as a much larger polymer rod than the standard brain implant used. The implant reduces tissue damage and inflammation. It spreads electrodes and microscopic channels across the brain layers. Traditional fibers, however, have an important limitation: They typically interact with brain tissue only at the end of the fiber, meaning researchers can stimulate or monitor just one location at a time.
“Most current brain implants are based on hard materials such as silicon, which can irritate the brain and trigger inflammatory reactions in the tissue. The new implant differs in that it is made of soft, plastic-like optical fibers and has a specially angled tip that makes it smaller and reduces the damage caused when it is placed in the brain,” says Kunyang Sui, who developed the mAxialtrode concept together with Christos Markas, an associate professor at DTU.
The effectiveness of the experiment in mice suggests that it may be used to treat neurological conditions like epilepsy. The apparatus successfully recorded electrical activity from both shallow and deep brain regions in living mice, activated nerve cells with blue and red light, and administered drugs at delivery points that were almost three millimeters apart.
This new development shows unprovoked seizures brought on by abrupt spikes by electrical activity. The implant, mAxialtrode, is mainly meant to be used as a research tool for studying epilepsy, memory, and decision-making.Kunyang Sui warns that it is still far from routine clinical use. It still requires extensive testing and regulatory approvals before patient applications. In the long run, researchers say the technology may also have therapeutic applications. If this technology develops, it will eliminate the need for several stiff implants that harm the tissue they are intended to read in order to investigate brain conditions like epilepsy.
Looking back, the Food and Drug Administration approved deep brain stimulation (DBS) for Parkinson’s disease in 2002, allowing surgeons to implant electrodes that deliver continuous electrical pulses to specific brain regions. DBS became the first major clinically successful implanted brain stimulation device. Demonstrated in 2005, Karl Deisseroth’s lab at Stanford showed that light-sensitive proteins from algae could be expressed in mammalian neurons, allowing precise control of neural activity with light pulses. The technique, called optogenetics, transformed how researchers manipulate brain circuits. As the world progresses, technology like this can help redefine major diseases for the better.
