A research team led by Dr MATSUO Toshihiko at Okayama University has developed OURePTM, a photoelectric dye-coupled thin-film device capable of stimulating degenerated retinal tissues.
OURePTM has been developed to generate electric potential changes by exposing to light, to stimulate tissues as in pacemakers for the heart or neurostimulators used for epileptic fits.
The research team has designed the OURePTM as a fine polyethylene film, created by placing polyethylene between two aluminium plates and melted by applying high pressure. The film undergoes a chemical reaction upon combining with a photoelectric dye.
According to the study recently published in Advanced Biomedical Engineering, the photoelectric dye-coupled film is placed on an electric potential-measuring device and exposed it to flashing light.
When the light hit the film, waves of electric signals were observed on the surface, and to test the film’s ability to stimulate tissue, retinal tissues of rats with retinal dystrophy, a retinal degenerative disorder, were procured.
The retinal tissues of healthy rats were brought to close contact with a multielectrode array and exposed to light, which resulted in the generation of electric signal waves. The multielectrode array is a device used to measure electrical signals from biological tissues.
The same procedure is performed with the dystrophic retinal tissue, but no signals were observed. When the photoelectric dye-coupled film was placed on top of the dystrophic tissues, the electric signals were induction in response to bouts of light.
The above procedure confirmed that a control film, without the photoelectric dye has failed to induce electric signals in the tissues.
The Okayama University research team said: “The current study provides direct evidence for the ability of the photoelectric dye-coupled polyethylene film to elicit electroretinogram-like response and action potential spikes in degenerative retina.”
A nylon mesh was used to keep the dystrophic tissues and the multielectrode array detector in closer contact, to measure these electric signals more precisely, and the study showed that photoelectric dye-coupled film is set to boost the electrical impulses within the degenerated retina.
Retinitis pigmentosa is a condition where photoreceptors of the eye slowly die, resulting in blindness. The study demonstrates the prosthetic value of OURePTM in potentially replacing the lost photosensitivity of the cells.