Release date: 2018-03-09
Doi:10.1038/s41467-018-03212-0
Recently, an invention published online by the research team of Zhongshan Hospital affiliated to Fudan University in Nature Communications is expected to bring hope for the treatment of retinal degenerative diseases. They bring an artificial photoreceptor that makes blindness small. The mouse responded again to the light!
Artificial photoreceptors are a research hotspot in recent years. Such devices are expected to connect to the damaged retina and artificially convert light signals into nerve signals to help patients see the light again. However, such devices have their own limitations - in order to generate and conduct signals, they need to implant an additional microelectronic processor, which limits the application of artificial photoreceptors in the body. If this limit can be broken, it will undoubtedly expand the application prospects of such devices.
This is the breakthrough of this research team. Professor Zheng Yufeng and Professor Zhang Jialu from Fudan University and colleagues have developed a titanium dioxide nanowire array coated with a gold nanoparticle layer. This innovative material can be used as an artificial photoreceptor to replace the function of key cells in the retina. In particular, due to the special properties of these materials, they are capable of generating voltage under the stimulation of light, which is expected to stimulate adjacent neurons and produce a visual response.
â–²The design of such materials (Source: "Nature Communications")
The effect of this special material was verified in mouse experiments. The researchers found that they reshaped the response of retinal ganglion cells to green, blue, and near-ultraviolet light. In the spatial dimension, new materials can achieve resolutions better than 100 microns!
Are these responses from the signals transmitted by the retinal bipolar cells to the ganglion cells under the action of photoreceptors? Or is it directly from the direct activation of the latter? This is an important issue. Only the former indicates that artificial photoreceptors can perform retinal function under normal conditions. To distinguish between the two, the researchers further applied glutamate receptor antagonists in experimental mice. Under normal conditions, such antagonists block the signaling of bipolar cells to ganglion cells. Subsequent studies have shown that the response of ganglion cells to light disappears after just 4 minutes of administration of such antagonists. When the researchers washed away the antagonists, the responses were restored. The results of this study clearly show that such artificial photoreceptors well preserve the proper functioning of the retinal loop.
â–²We expect this research to benefit patients with visual defects as soon as possible (Source: Pixabay)
Subsequent studies found that neurons in the primary visual cortex responded to light after implantation of the nanowire array. Although we can't confirm from the mouse mouth that they can see the light again, all kinds of experimental results support this view.
Researchers have pointed out that such technology is expected to be applied to human patients in the future, bringing new treatment options for patients with retinal degenerative diseases. We expect this invention from Chinese scientists to be applied as soon as possible!
Reference materials:
[1] Nanowire arrays restore vision in blind mice
Source: Academic Jingwei
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