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Nanotechnology targets degenerative cascades in retina
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LAS VEGAS — Nanotechnology can be used to restore visual function at a molecular or cellular level, a speaker said at the American Academy of Ophthalmology meeting.
Artificial photoreceptors and free radical scavengers can be used to restore vision in patients with macular degeneration, retinitis pigmentosa and other chronic diseases, Emmanuel Chang, MD, PhD, said during a press briefing on “Innovations in vision: Nanotech, nearsightedness and neuro-ophthalmology imaging.”
“[Nanotechnology] allows the leveraging of unique molecular structures toward unique biological applications,” Chang said.
Retinal prostheses such as the Argus II (Second Sight) are electronic-based, Chang said, and in such devices, electrodes range from 50 µm to 200 µm.
A nano-photoreceptor can operate on a molecular and cellular level, has the potential for true cellular photoreceptor regeneration, has minimal energy requirements and may be self-powered, Chang said.
“Because they’re organic and non-metallic, there is no electrolytic degeneration or corrosive components, so they have a durable lifetime,” he said.
A silicon wafer is photoresponsive, like a solar energy cell, he said.
“We can grow nanowires off it and control the density and the length, and generate either holes or electrons for either hyperpolarization or depolarization of the neuron,” he said.
Hydrocarbon clusters are focused on free radical scavenging, Chang said.
“In ischemic retinal injuries, the primary issue is reperfusion/restoration of blood flow,” he said. “That reperfusion injury generates a burst of reactive oxygen species or radicals. They can then damage DNA and proteins and trigger cell apoptosis or trigger inflammatory cascades that drive further radical formation. These free radical scavengers basically have high aromatic rings. These aromatic rings have an abundance of electrons that thereby annihilate and remove the radical that can cause damage instead of transferring or having a chemical bond with typical antioxidants in the body like vitamin E, so during periods of intense [reactive oxygen species] generation, instead of being depleted, it can compensate or react during those high radical formation periods.”– by Matt Hasson
Disclosure: Chang reports no relevant financial disclosures.