UC Irvine researchers have created a retina from human embryonic stem cells, the first time they've been used to create a three-dimensional tissue structure. The eight-layer, early stage retina could be the first step towards the development of transplant-ready retinas to treat eye disorders such as retinitis pigmentosa and macular degeneration.
"We made a complex structure consisting of many cell types," said study leader Hans Keirstead. "This is a major advance in our quest to treat retinal disease."
In previous studies on spinal cord injury, the Keirstead group came up with a method to direct human embryonic stem cells to become specific cell types, a process called differentiation.
The team used the same technique to create the multiple cell types necessary for the retina. The greatest challenge, Keirstead said, was in the engineering. To mimic early stage retinal development, the researchers needed to build microscopic gradients for solutions in which to bathe the stem cells to initiate specific differentiation paths.
"Creating this complex tissue is a first for the stem cell field," Keirstead said. "Dr Gabriel Nistor in our group addressed a really interesting scientific problem with an engineering solution, showing that gradients of solutions can create complex stem cell-based tissues."
Retinal diseases are particularly damaging to sight. More than 10 million Americans suffer from macular degeneration, the leading cause of blindness in people over 55. About 100,000 have retinitis pigmentosa, a progressive, genetic disorder that usually appears in childhood.
“What’s so exciting with our discovery,” Keirstead said, “is that creating transplantable retinas from stem cells could help millions of people, and we are well on the way.”
The UCI researchers are testing the early-stage retinas in animal models to learn how much they improve vision. Positive results will lead to human clinical trials.