The technology enables completely new types of implants that can be used to stimulate nerve cells, according to a press release from TU Graz, whose researchers are developing them together with Med-Uni Graz, the University of Zagreb and CEITEC (Central European Institute of Technology ) have developed.
Farbpigmente as Basis
The basis for this are color pigments from the food industry, such as those used in organic solar cells: The pigments are vapour-deposited to form a layer just a few nanometers thick, where they convert light into an electrical charge – just like in organic solar cells. Nerve cells that adhere to the foil (they are first pipetted onto the foil, “wander” on it and grow firmly, note), react to this charge and in turn fire electrical impulses with which they stimulate other nerve cells.
Short flashes of light
In cell biological experiments, the researchers have now been able to demonstrate this process for the first time. Cultured nerve cells, which grew directly on the film, were stimulated by several short flashes of light, each lasting a few milliseconds, with a wavelength of 660 nanometers (red light) and reacted as hoped: they generated so-called action potentials, which are essential for communication between nerve cells. The researchers have published the results of their electrophysiological measurements and computer simulations in the journal Advanced Materials Technologies.
The corresponding author Theresa Rienmüller from the Institute for Health Care Engineering at TU Graz spoke of a paradigm shift: “In contrast to the current electrical stimulation using metal electrodes, our pigment foils represent a completely new way of stimulating nerve cells.” The foils are so thin that they are light can be implanted.
For humans and animals
During the treatment, the nerve cells would then be irradiated with red light, which can penetrate deep into the body without harm. “We think that short-term treatments can lead to long-term therapeutic effects. These experiments are currently being researched,” says Rainer Schindl, electrophysiologist at the Chair of Biophysics at Med-Uni Graz and supervisor in the project.
In the future, there will no longer be any need for complex cabling, which in turn reduces the risk of infection after invasive procedures because there are no longer any hoses or cables that have to run out of the body to the outside. Thanks to their organic nature, the pigment foils are extremely well tolerated – for both human and animal cells.
Brain injuries and pain therapies
The researchers see possible applications in severe brain injuries: Here, the stimulation of nerve cells can accelerate the healing process and prevent complications by “preventing the nerve cells from dying”, according to first author Tony Schmidt from the Chair of Biophysics at Med-Uni Graz.
The researchers also see potential in other neurological injuries or in pain therapy. The technology can also be used to create novel retinal implants. Further research is needed before the pigment film finds its way into clinical use.