Lab-grown retinal cells restore vasculature in mouse studies

Stem cell-derived retinal endothelial cells offer new disease modeling tool

Researchers at Duke University generated retinal endothelial cells from human induced pluripotent stem cells for the first time.¹ The cells, termed iRECs, integrated into damaged retinal tissue in mouse models and restored vascular structure and function. The findings were published in Nature Biomedical Engineering.¹

Retinal microvascular diseases, including diabetic retinopathy, involve breakdown of the inner blood-retina barrier, a tightly regulated vascular structure essential to retinal health. Supply of retinal endothelial cells for research has historically depended on donor tissue, limiting availability and driving up cost. A renewable, lab-grown source could expand access for both disease modeling and therapeutic development.²

"We're confident we can create excellent human tissue models in the lab to help better understand these diseases and uncover therapies," said Parker Esswein, a PhD student in the Gerecht laboratory and first co-author of the study, in a statement.²

Trial design and mouse model outcomes for retinal repair

The research team differentiated human iPSCs into retinal endothelial cells using Wnt-beta-catenin signaling, driven primarily by Norrin-Frizzled4 activation.¹ These iRECs demonstrated genetic, protein, and functional markers consistent with native retinal endothelium, along with distinguishing retinal-specific features. When injected into oxygen-induced retinopathy mouse models, iRECs integrated into the host vascular network and revascularized ischemic retinal tissue. Vaso-obliteration and neovascularization areas were both significantly reduced compared with phosphate-buffered saline-injected control eyes.¹ The treated networks also showed vascular volumes and lumen diameters aligning more closely with healthy retinal capillary values than the pathological vasculature seen in controls. Investigators additionally built microphysiological, chip-based iBRB models incorporating iRECs and stem cell-derived retinal pericytes, producing perfusable microvascular networks that recapitulated barrier morphology and function in both healthy and diabetic conditions.¹

The work was federally funded in part through the National Eye Institute, along with NASA and the National Science Foundation.³

Diabetic retinopathy modeling and pipeline for future eye disease research

To model diabetic retinopathy, researchers exposed iRECs to elevated glucose and low oxygen conditions.¹ The cells showed disrupted tight junction protein localization and decreased barrier function under these conditions, recapitulating clinical features of diabetic retinopathy. Safety and functional assays showed no differences in cell viability between control and diabetic-treated groups, supporting the reliability of phenotypic and functional changes observed under diabetic conditions. Prior clinical experience with iPSC-derived cell therapies in ophthalmology, including a hiPSC-based transplant for age-related macular degeneration, showed feasibility without safety signals, though without improvement in that case.¹

"Using human stem cells, we generated the cells found in retinal blood vessels, paving the way for new therapeutic approaches," said Sharon Gerecht, PhD, Paul M. Gross Distinguished Professor and chair of biomedical engineering at Duke, in a statement.²

For optometrists, the work remains preclinical and does not change current prescribing, monitoring, or referral protocols for diabetic retinopathy or other retinal microvascular disease. It signals a future direction for research tools and potential cell-based therapies optometrists may see referenced in continuing education or co-management discussions with retina specialists. Patent applications covering both the therapeutic and disease-modeling applications of the technology are pending, according to Duke.²

References:

1. Lin YY, Esswein P, Ramirez L, Warren E, Nicenboim J, Gerecht S. Derivation of functional retinal endothelial cells from human pluripotent stem cells for therapeutics and modelling. Nat Biomed Eng. Published online June 30, 2026. doi:10.1038/s41551-026-01712-9

2. Kingery K. Lab-grown retinal cells show promise for new eye therapies. Duke Pratt School of Engineering. Published June 30, 2026. Accessed July 15, 2026. https://pratt.duke.edu

3. NEI-funded study details new lab-grown retinal cells for eye disease research. News release. National Institutes of Health. June 30, 2026. Accessed July 15, 2026. https://www.nei.nih.gov/research-and-training/research-news/nei-funded-research-grows-retinal-blood-vessel-cells