Lab-Grown Retinal Cells Bring Bright New Hope for Future Vision Treatments

A hopeful step forward in eye health has emerged from Duke University, where biomedical engineers have used lab-grown human retinal blood vessel cells to restore retinal function in mice with vision-threatening disease.

The work offers encouraging possibilities for people affected by retinal vascular diseases, including conditions similar to diabetic retinopathy, a major cause of vision loss among working-age adults.

In the study, researchers injected specially grown retinal endothelial cells into mice with damaged retinas. These cells were able to join with the existing tissue, help rebuild blood vessels, and support the return of retinal function. In images from the research, a mouse retina showed striking improvement after treatment with the human lab-grown cells.

The team, led by Professor Sharon Gerecht, created the specialized retinal blood vessel cells using induced pluripotent stem cells, known as iPSCs. These remarkable cells are made by reprogramming ordinary adult cells back into a stem-cell-like state, allowing them to be transformed into many different cell types in the body.

The discovery behind this technology earned Shinya Yamanaka the 2012 Nobel Prize, shared with Sir John Gurdon, for identifying the “Yamanaka factors” that made this transformation possible.

At Duke, researchers showed for the first time that iPSCs could be guided into becoming the specialized endothelial cells that help maintain healthy blood vessels in the retina. They also demonstrated that these cells could form functional retinal vascular tissue in the lab, opening a promising path for studying and treating eye diseases.

“Retinal vascular diseases affect millions of people, but our understanding remains limited, hindering our ability to discover and develop new therapeutics,” said Professor Sharon Gerecht, who led the research published in Nature Biomedical Engineering.

“Using human stem cells, we generated the cells found in retinal blood vessels, paving the way for new therapeutic approaches.”

The retina is closely connected to the brain and is considered part of the central nervous system. Like the brain, it has a protective barrier that carefully controls what can enter and leave, including oxygen, nutrients, water, and medicines.

That protective system is essential for keeping the retina healthy, but it also makes treatment challenging. Retinal endothelial cells form part of this barrier, and when they stop working properly, vision can be at risk.

“When this specialized blood vessel tissue begins to break down, it can cause a lot of different diseases that lead to vision loss,” said study first co-author Parker Esswein, a PhD student working in the Gerecht lab. “While there are sources of retinal endothelial cells, being able to grow a continuous supply from scratch could offer many advantages for those working in the field.”

Today, retinal endothelial cells are typically collected from real patients and grown in the lab, which can make them costly, limited in supply, and variable from sample to sample. The Duke team set out to make the process more accessible and reliable by growing the cells from iPSCs instead.

To do this, the researchers began with commercial iPSCs and used established methods to turn them into common endothelial cells, the type that lines blood vessels throughout the body. Then, with a specialized mix of growth factors, they encouraged those cells to become the precise kind found in the retina.

Once the cells had been created, the team tested whether they could behave like real retinal blood vessel cells. In the lab, the cells formed networks and structures similar to those found in the body.

The researchers then exposed the tissue to low oxygen and high glucose levels, conditions often linked to diabetes. These stressors are “fundamental” triggers of diabetic retinopathy, which is the leading cause of vision loss in working-age people in the United States. Under those conditions, the tissue barrier broke down in a way that mirrored what happens in patients.

The next joyful milestone came when the lab-grown cells were tested in mice. When injected before any actual vision loss had occurred, the cells successfully became part of the existing retinal tissue and helped form strong blood vessels with strong barriers.

“The tests showed that these lab-grown cells have promise for preventative treatments, especially since they should be easier and cheaper to obtain using our technique,” said Esswein.

The discovery could also make it easier for scientists to study eye diseases in the lab and search for new medicines.

“While our benchtop experiments did not attempt to model a wide variety of specific eye diseases in these studies, we’re confident we can create excellent human tissue models in the lab to help better understand these diseases and uncover therapies.”

The Duke team is now preparing to explore more uses for the retinal endothelial cells, both in the lab and through developing industry partnerships. The researchers also have a patent pending for the stem cell-based therapies and for using the cells in laboratory models for drug discovery and testing.

With this progress, scientists are moving closer to a future where damaged retinal blood vessels may be repaired more easily, more affordably, and with greater precision—bringing renewed hope to millions of people facing vision loss.