Therapies that deliver electrical stimulation to the brain to treat neurodegenerative diseases like Parkinson’s and Alzheimer’s have been found to be effective. To deliver this deep brain stimulation (DBS), electrodes are implanted in areas of the brain through small holes drilled in the skull. A pacemaker-like device is also inserted under the skin of the chest to power the electrodes.
Inserting electrodes into the brain has risks, one being that the leads carrying those electrodes can be misplaced, migrate, or break. Researchers from the Uhlan National Institute of Science and Technology (UNIST), South Korea, have developed a biodegradable, wirelessly activated ‘bio-paper’ implant that avoids these issues.
“The developed material offers personalized treatment options tailored to individual needs and physical characteristics, simplifying treatment processes, enhancing flexibility, and versatility in electrical stimulation-based clinical applications,” said the study’s lead author, Jun Kyu Choe, from UNIST’s Department of Materials Science and Engineering.
The material is made of synthesized magnetoelectric nanoparticles (MENs), comprising a magnetostrictive core and a piezoelectric shell that can generate an electric field when an external magnetic field is applied. In basic terms, the magnetostrictive core converts the applied magnetic field into mechanical strain, which the piezoelectric shell converts into an electric field.
The core-shell MENs are integrated into electrospun biodegradable nanofibers to produce a flexible and lightweight sheet that is paper-like, porous, and biodegradable. The material’s porosity ensures that important small molecules like oxygen and nutrients can pass through it. It was almost completely biodegraded after two months.
“The combination of nanoscale magnetoelectric and biodegradable fibrous materials offers advantages over traditional system-level wireless electronic devices that rely on intricate assembly of bulky components that cannot be redesigned post-fabrication,” said the researchers.
Its physical properties mean the ‘paper’ will conform to curved, complex surfaces – like the brain’s – and can be cut, rolled, and folded while retaining functionality. Indeed, it was flexible enough for the researchers to create a cylinder with a radius of 400 µm that could be wrapped around a nerve and used to regenerate it. It can also be made to the required size.
“The bioelectric paper, in principle, can be simply customized to organ-scales of several tens of centimeters or miniaturized to sub-micrometer scales for minimally invasive operations, and the magnetoelectricity or microstructure does not depend on its scale,” said Jiyun Kim, one of the study’s corresponding authors. “Overall, our bioelectric paper, with facile and broad application, could open up a new scheme toward minimally invasive and biodegradable wireless bioelectronic implants.”
The study was published in the journal Advanced Materials.
Source: UNIST