Researchers created eye tissue using patient stem cells and 3D bioprinting to better understand the mechanics underlying blinding illnesses. The National Eye Institute (NEI), a division of the National Institutes of Health, developed a method for printing a mixture of the cells that make up the outer blood retina barrier, a layer of eye tissue that supports the retina′s light-sensing photoreceptors. The method makes it possible to research age-related macular degeneration (AMD) and other degenerative retinal illnesses using a theoretically limitless supply of patient-derived tissue. 

Three immature choroidal cell types were combined by researchers in a hydrogel: fibroblasts, which provide tissues, structure; pericytes, which are essential capillary constituents; and endothelial cells, which are the main constituents of capillaries. A biodegradable scaffold was then used by the scientists to print the gel. The cells developed into an extensive capillary network in just a few days. Retinal pigment epithelial cells were sown on the scaffold′s reverse side on day nine. Day 42 marked the full maturation of the printed tissue. The printed tissue resembled and behaved like the natural outer blood-retina barrier, according to tissue analysis, genetic testing, and functional testing.

When stressed, printed tissue showed signs of early AMD, including drusen deposits under the RPE, and the tissue degeneration progressed to late dry stage AMD. Low oxygen levels caused a wet AMD-like look with choroidal vascular hyperproliferation that moved into the sub-RPE zone. AMD, when treated with anti-VEGF medications prevented this vessel movement and overgrowth, and tissue morphology was recovered.

Researchers are hopeful that these tissue models can be very useful in translational applications, including therapeutics development.

(Source: https://health.economictimes.indiatimes.com/news/health-it/researchers-use-3d-bioprinting-to-create-eye-tissue/96535391)