Wireless Stimulation Technology Developed for Retinal Degenerative Diseases

An international research team, led by Prof. Dr. Sedat Nizamoğlu from Koç University's Department of Electrical and Electronics Engineering, has developed a wireless stimulation technology for retinal degenerative diseases that cause vision loss. The study, detailing an ultra-thin and biocompatible system designed to convert near-infrared light into biological electrical signals, was published in Science Advances.

Background on Retinal Degenerative Diseases

Retinal degenerative disorders currently affect millions globally and are characterized by a lack of curative treatments. Existing retinal implants face clinical limitations, often due to their bulky designs, complex electronic components, or the requirement for high-intensity visible light for activation.

Technology Overview: A Wireless Photovoltaic Nano-Assembly

To address these challenges, the Koç University researchers developed a photovoltaic nano-assembly. This system combines zinc oxide nanowire arrays with silver-bismuth-sulfide nanocrystals. The design allows for the conversion of near-infrared light into controlled electrical stimulation.

Near-infrared light was chosen for its ability to penetrate tissue more deeply and safely than visible light. The system operates at low light intensities, remaining below established ocular safety limits, and features a fully wireless, ultra-thin architecture. This design eliminates the need for external cables or complex electronic components.

Performance and Safety Evaluation

The system's performance was evaluated using retinal models derived from rats with vision loss. Experiments demonstrated strong, repeatable, and temporally precise responses in retinal neurons.

Comprehensive analyses indicated that the structure did not induce cellular stress or toxicity. It showed good cell viability, biocompatibility, and long-term stability, suggesting suitability for prolonged use. A negligible temperature increase was observed during operation, further supporting the safety profile of the approach.

Distinguishing Features and Broad Applications

This technology differentiates itself from existing retinal implants through its ultra-thin active layer, the use of near-infrared light rather than visible light, and its completely wireless design.

Prof. Dr. Sedat Nizamoğlu stated that this nanotechnological retinal implant approach could potentially restore vision for individuals diagnosed with macular degeneration and retinitis pigmentosa.

"Inorganic nanocrystals, recognized by the 2023 Nobel Prize in Chemistry, hold promise for retinal prosthesis technology when integrated into optimized nanoarchitectures." — Prof. Dr. Sedat Nizamoğlu

Prof. Nizamoğlu further added that this nanoscale system, operating with near-infrared light, offers an alternative to current approaches in terms of performance and may open new avenues for visual prosthetics and broader neuromodulation applications targeting electrically excitable tissues, including the brain, heart, and muscles.