Researchers grow artificial photoreceptors, transplant them in animals

Jul 22, 2013 18:01 GMT  ·  By

Several blind mice can now see again, all thanks to laboratory-grown photoreceptors that have been transplanted into their retinas.

Specialists say that this scientific breakthrough brings new hope to people who have lost their sight either as a result of old age, or because of various medical conditions.

Writing in the journal Nature Biotechnology, the researchers say that these mice were unable to see due to the fact that they had impaired photoreceptors, i.e. retinal rods and cones that are sensitive to light and which help animals pick up visual cues from their surroundings.

Medical Daily reports that, some time ago, scientists managed to restore sight to other blind mice by collecting immature rods from young specimens and transplanting them into adult rodents.

This time, they wished to see whether or not it might be possible to bypass the need for a donor, and use embryonic stem cells to engineer working photoreceptors.

Their experiments have proved a success. Thus, not only did the laboratory-grown photoreceptors survive inside the animals' bodies, but they also set up connections with the damaged retinas and the rodents' brains.

Since 2006, when the researchers first started experimented with this method of treating blindness, until present day, their success rate upped from 0.5% to 20%.

This means that, out of the total number of cells that are transplanted into a mouse, one fifth successfully establish connections with the retina and the brain.

The scientists claim that, although they still have some research to carry out, it will probably be less than five years until they roll out a clinical trial involving human patients.

“Before human clinical trials can commence, the mouse model will require significant optimization, for example increasing the efficiency of new photoreceptors to connect with the damaged retina.”

“However, there is no doubt that this breakthrough, either directly as the basis of a future cell therapy, or indirectly by expanding our knowledge, will significantly contribute to the fight against blindness,” argued Professor Chris Mason, now working as a stem cell biologist at University College London.