Fight Aging!

Researchers have made the first steps towards generating a soft synthetic replacement for the retina that is capable of generating electrical signals in response to light. A great deal of work is yet to be accomplished in order to turn this initial proof of concept into an implant that can restore some form of light-sensitivity and sight to an individual with a damaged retina, but it is an interesting alternative to the electrode grid approach that has taken off in recent years. Initial practical models will likely work in a similar fashion, producing phosphenes in a pattern that corresponds to the shading of the current field of view rather than true sight, but a continuous soft medium should be capable of greater detail and contrast than an electrode grid, at least in principle.

Until now, all artificial retinal research has used only rigid, hard materials. The new research is the first to successfully use biological, synthetic tissues, developed in a laboratory environment. The study could revolutionise the bionic implant industry and the development of new, less invasive technologies that more closely resemble human body tissues, helping to treat degenerative eye conditions such as retinitis pigmentosa. Just as photography depends on camera pixels reacting to light, vision relies on the retina performing the same function. The retina sits at the back of the human eye, and contains protein cells that convert light into electrical signals that travel through the nervous system, triggering a response from the brain, ultimately building a picture of the scene being viewed.

Researchers developed a new synthetic, double layered retina which closely mimics the natural human retinal process. The retina replica consists of soft water droplets (hydrogels) and biological cell membrane proteins. Designed like a camera, the cells act as pixels, detecting and reacting to light to create a grey scale image. "The synthetic material can generate electrical signals, which stimulate the neurons at the back of our eye just like the original retina." Unlike existing artificial retinal implants, the cell-cultures are created from natural, biodegradable materials and do not contain foreign bodies or living entities. In this way the implant is less invasive than a mechanical device, and is less likely to have an adverse reaction on the body. At present the synthetic retina has only been tested in laboratory conditions, but the researchers are keen to build on the initial work and explore potential uses with living tissues. The next phase of the work will see the team expand the replica's function. Working with a much larger replica, the team will test the material's ability to recognise different colours and potentially even shapes and symbols.

Link: http://www.ox.ac.uk/news/2017-05-04-oxford-student-creates-first-synthetic-retina