The deterioration of photoreceptors is a significant factor in blindness. Patients with localized retinal degeneration may benefit from additional vision function if their blind human retina is made sensitive to near-infrared light. Researchers restored the light sensitivity of damaged photoreceptors using tunable, near-infrared devices. An antibody to temperature-sensitive ion channels was coupled with gold nanorods that could sense infrared light. Infrared light triggered the coupled ion channels when the nanorods absorbed light and turned it into heat. These ion channels were effectively targeted to cone photoreceptors in a mouse model of retinal degeneration, and responses to near-infrared light could be seen.
Gold nanorods bound to temperature-sensitive engineered transient receptor potential (TRP) channels were used by researchers to elicit near-infrared light sensitivity. Infrared light triggered the coupled ion channels when the nanorods absorbed light and turned it into heat. In a mouse model of retinal degeneration, the researchers expressed mammalian or serpent TRP channels in light-insensitive retinal cones. Mice could execute a learned light-driven behavior because near-infrared stimulation increased activity in cones, ganglion cell layer neurons, and cortical neurons.
Using nanorods of various lengths and designed channels with various temperature limits, they tuned responses to various wavelengths and radiant powers. They specifically targeted TRP channels in human retinas, allowing distinct cell types to be postmortem activated by near-infrared light.
Related Content: PET Imaging In Patients With Pulmonary Tuberculosis