Using induced pluripotent stem cells (iPSCs), National Eye Institute researchers have developed a therapy to prevent blindness in dry age-related macular degeneration (AMD). Positive animal study data have now set the stage for a human trial.
AMD involves the loss of the retinal pigment epithelium (RPE), a thin cell layer that protects photoreceptor cells in the retina. By replacing the dying RPE cells, the iPSC therapy would save the eye before vision loss occurs.
The researchers took blood cells from AMD subjects, converted them into iPSCs, and directed them to become RPE tissue. The cells were grown in a single layer on a biodegradable scaffold that stimulates integration when they reach the retina.
As iPSC can multiply uncontrollably and develop into cancer, its use in humans has been limited. However, the researchers’ process was designed to avoid cancer-causing mutations.
Ten weeks after the lab-made RPE cells were implanted in animal retinas, studies demonstrated that they had integrated within the retina and safely reversed degeneration.
Further tests indicated that the implanted RPE cells exhibited “phagocytosis,” which is vital for maintaining healthy-sized photoreceptors.
Source: FierceBiotech.com, January 16, 2019