3D Retina Brings Scientists Closer to Better Models and Therapies
For the first time, researchers have used induced pluripotent stem cells — stem cells derived from the reprogramming of mature human cells — to create a three-dimensional retina with functional photoreceptors, the cells that make vision possible. The new model will enable scientists to better understand retinal development and function, and provide a powerful platform for creating and testing future therapies. Results from the study, led by M. Valeria Canto-Soler, Ph.D., at Wilmer Eye Institute, Johns Hopkins School of Medicine, were reported in Nature Communications.
“This is the first time that researchers have been able to create photoreceptors in a dish that respond to light,” says David Gamm, M.D., Ph.D., a study author and Foundation-funded researcher at the University of Wisconsin-Madison. “It provides some confidence that these cells could make functional photoreceptors when transplanted into a patient.”
“While emerging treatments comprised of individual retinal cell types continue to advance into human studies, the progress being made in developing three-dimensional retinas is bringing us closer to the real thing,” says Stephen Rose, Ph.D., chief research officer, Foundation Fighting Blindness. “The better we can duplicate the naturally occurring human retina, the better we can develop models and vision-saving therapies.”
Dr. Gamm explains that three-dimensional retinas, which have been developed by different labs around the world, have the capacity to produce all the major retinal cell types found in a naturally developed retina, although some survive longer than others in a dish.
Dr. Gamm cautions that before the structures could be evaluated in humans, they would need to be developed using good manufacturing practices, or GMP, which ensures that they meet clinical standards for safety and quality.
It is also possible that transplanting intact donor retinal structures at a relatively mature stage of development may not be the optimal solution. Instead, Dr. Gamm says it might be preferable to transplant suspensions of more immature photoreceptor cells, which also do not take as long to produce.
Regardless of the strategy, functional integration of transplanted cells with the recipient’s retina remains the biggest challenge for retinal scientists. “It is the Holy Grail for the stem-cell field,” says Dr. Gamm. “We just need to make smart decisions moving forward, and we’ll get closer to the goal with each research study. This won’t happen overnight, but the field is steadily moving in the right direction.”