Zurich researchers repair severed spinal cord

(CONNECT) Researchers have found a new and minimally invasive way to repair the severed spinal cord of living beings. A research team from the Swiss Federal Institute of Technology in Zurich (ETH) and the University of Zurich has already succeeded in doing this in zebrafish and mice without the use of external electrodes or cables. According to an ETH press release, the "extremely promising results" from this study still require intensive testing before they can be used on humans.

The team has developed a biohybrid microrobot for its completely new approach. Living neural progenitor cells (NPCs) are connected to magnetoelectric nanoparticles in such a way that they can then be directed to exactly the right place with the help of external magnets, where they then stimulate the stem cells. "We can use microrobotic control to make treatment more precise and minimally invasive," says senior scientist and first author of the study Hao Ye.

From the combination of these special nanoparticles and the precursor cells, the researchers fabricate NPC bots just six micrometers in size. Depending on the test variant, they need hundreds of thousands of these microrobots for cell-based studies and several million for animal studies. They have developed lab-on-chip systems measuring around 1 square centimeter for their production.

In zebrafish larvae, the microrobots were injected precisely into the injured area and electromagnetic fields were generated. After only three days, the zebrafish showed almost normal swimming and exploratory behavior. In mice, the severed nerve cells were reconnected after 28 days. This is all the more remarkable as, unlike zebrafish, the spinal cord of mice does not normally regenerate. No harmful side effects were observed in either case.

"The reproducible and scalable production of microrobots with our lab-on-a-chip system shows that the platform's application potential goes beyond basic research," explains Professor Salvador Pané i Vidal from ETH's Multi-Scale Robotics Lab. The process could also be adapted for cardiology, oncology, wound healing and other targeted regenerative therapies, for example. ce/mm