UCL scientists performed the first successful transplant of light-sensitive photoreceptor cells grown from embryonic stem cells, according to a news release.
The cells were extracted from a synthetic retina, cultivated "in a dish" from embryonic stem cells. The new cells were transplanted into night-blind mice and they develop normally, forming the correct nerve connections needed to transmit visual information to the brain, according to UCL.
The study was published in the journal Nature Biotechnology.
The findings show embryonic stem cells may have the potential to provide healthy photoreceptors for retinal cell transplantations to treat blindness in humans, researchers suggest.
"The loss of photoreceptors - light sensitive nerve cells that line the back of the eye - is a leading cause of sight loss in degenerative eye diseases such as age-related macular degeneration, retinitis pigmentosa and diabetes-related blindness," UCL said in a news release.
There are two types of photoreceptor in the eye: rods and cones. Rods help you see better in the dark since they are sensitive to low levels of light.
"Previous work by Professor Robin Ali and his team at the UCL Institute of Ophthalmology and Moorfields Eye Hospital has shown that transplanting immature rod cells from the retinas of healthy mice into blind mice can restore their sight," UCL said. "UCL However, in humans this type of therapy would not be practical for the thousands of patients in need of treatment."
Ali's research team used new techniques in the study, including 3D culture and differentiation of mouse embryonic stem cells, to grow retinas that contained different nerve cells needed for sight.
Professor Ali, UCL Institute of Ophthalmology and Moorfields Eye Hospital, who led the research, released the following statement:
Over recent years scientists have become pretty good at working with stem cells and coaxing them to develop into different types of adult cells and tissues. But until recently the complex structure of the retina has proved difficult to reproduce in the lab. This is probably because the type of cell culture we were using was not able to recreate the developmental process that would happen in a normal embryo.
The new 3D technique more closely mimics normal development, which means we are able to pick out and purify the cells at precisely the right stage to ensure successful transplantation. The next step will be to refine this technique using human cells to enable us to start clinical trials.
To read more about the retina research, click here.
