Optogenetic testing shows vROs produce precise, strong light-evoked responses, including ON, OFF, and ON-OFF pathways after weeks of maturation.

The vascularized retinal organoids preserve developmental processes and exhibit higher survival and functional maturity of retinal ganglion cells, with more active electrical signaling than non-vascularized counterparts.

Pre-cultured endothelial cells integrate well into organoid spheres, enabling sustained maturation and the emergence of an in vitro optic nerve-like pathway from photoreceptors to ganglion cells.

The vascularized approach preserves developmental processes while boosting survival and maturation, marking a major step for reliable drug testing and disease modeling in eye conditions.

This approach engineering vascularized organoids enables nutrient and oxygen transport via lumen-like networks, enhancing retinal ganglion cell survival and maturation.

Vascularized retinal organoids model hypoxic responses and can be used to study diseases such as retinopathy of prematurity, informing potential therapies.

The research appears in Cell Stem Cell under the title 'Retinal ganglion cell survival and functional maturation in transiently vascularized human retinal organoids,' published January 12, 2026.

This advance enables more accurate retinal development studies, disease mechanisms, drug testing, and future therapies through a sophisticated vascularized retinal model.

Funding for the work comes from multiple sources, including the Volkswagen Foundation, German Research Foundation, Pro Retina Foundation, TRA Life and Health of the University of Bonn, Cluster of Excellence ImmunoSensation3, and the Federal Ministry for Economic Affairs and Climate Action.

An international team led by Prof. Volker Busskamp at University Hospital Bonn, the University of Bonn, and the Institute of Molecular and Clinical Ophthalmology Basel developed vascularized retinal organoids by integrating pre-cultured endothelial cells to form lumen-like networks that supply nutrients and oxygen to retinal ganglion cells, improving their survival.

The researchers created vascularized human retinal organoids (vROs) by incorporating endothelial cells to build artificial vessels within lab-grown retinas.