Researchers at the National Eye Institute (NEI), in the United States, have developed a new 3D bioprinted eye tissue that can help identify age-related diseases that cause macular degeneration, leading patients to blindness.
The scientists imprinted a combination of cells that form the barrier known as the blood-retina on the outside of the eye. This artificial eye tissue contains an almost unlimited amount of retinal light-sensitive photoreceptors, allowing for further study into cellular degeneration.
“We know that problems in the macula start at the outer blood-retina barrier. However, we do not know the mechanisms of initiation and progression of the disease, due to the lack of physiologically available human models”, explains researcher Kapil Bharti, lead author of the study.
bioprinted eye tissue
To develop the 3D-printed eye tissue, the scientists created a hydrogel by mixing three types of immature choroidal cells: pericytes and endothelial cells — important components of capillary systems — and fibroblasts, which give structure to eye tissues.
The gel was applied to a biodegradable substrate, where the cells could grow in a controlled manner. On the ninth day of development, the researchers implanted the retinal pigment epithelium cells and, after 42 days, the bioprinted tissue was ready to be used.
“By printing these cells, we are facilitating the exchange of information needed to investigate the normal anatomy of the retinal outer blood barrier. In this way, it is possible to study how diseases arise, increasing the effectiveness of treatments”, adds Bharti.
Diseases that cause blindness
Genetic tests and functional analyzes have shown that the bioprinted tissue is similar to the natural outer blood-retinal barrier, both in appearance and in its physical behavior. Under stress conditions, the artificial tissue exhibited early characteristics of macular disease, progressing to a more advanced stage with increasing stimulus.
Low oxygen levels caused an appearance similar to age-related macular degeneration, with choroidal vascular hyperproliferation. When applied to the bioprinted tissue, the drugs reduced the formation and migration of blood vessels, showing that the artificial material can be used as a basis for studies on the origin of the disease.
“Our collaborative efforts have resulted in very relevant retinal tissue models for degenerative eye diseases. These models have many potential uses in translational applications, including the development of new therapies in the future”, concludes researcher Marc Ferrer, co-author of the study.
Source: NEI
