American scientists have successfully developed pig retinal organoids, opening new pathways for testing and advancing stem cell therapies for vision loss.
Stem cell therapy is a promising approach to restoring lost light-sensitive photoreceptors that are crucial for vision. However, Dr David Gamm, from University of Wisconsin–Madison, said testing these therapies in animal models has been difficult because human cells are not compatible in other species and are quickly rejected when transplanted.
“Pig and human retinas share many key features, making pigs ideal for modelling human retinal disease and testing ocular therapeutics,” Dr Gamm said.
“By testing ‘human-equivalent’ photoreceptors in pigs, we can get a better sense of what these cells can do if they are not immediately attacked by the host animal.”
In a new study, published in Stem Cell Reports,1 the Gamm Lab partnered with researchers at the Morgridge Institute for Research to develop lab-grown pig retinal organoids.
Organoids are small tissue clusters – about the size of a large pin head – made up of hundreds of thousands of cells, which allow scientists to replicate the cellular interactions and conditions in a human tissue or organ, but in the controlled environment of a lab dish.
First author Kim Edwards said it is the first time people have made pig retinal organoids, and the first time that there’s been a comparison of human versus another species of retinal organoids.2
The findings could pave the way for more effective stem cell-based treatments for vision loss, offering hope for millions affected by retinal degenerative diseases.
Next Steps
The next phase of the research involves transplanting pig-derived photoreceptors into pig retinas to assess their ability to integrate with existing retinal structures and potentially restore vision.
“We’re excited to show that you can grow these retinal organoids from different species and that a lot of groups across the world are starting to make them,” said Ms Edwards. “It all starts with having good stem cells.”
The findings could pave the way for more effective stem cell-based treatments for vision loss, offering hope for millions affected by retinal degenerative diseases.
References
- Edwards KL, Moore B, Gamm D, et al. Robust generation of photoreceptor-dominant retinal organoids from porcine induced pluripotent stem cells. Stem Cell Reports. 2025;20. doi: 10.1016/j.stemcr.2025.102425.
- University of Wisconsin-Madison, UW vision researchers explore stem cell replacement therapy using lab-grown photoreceptors as promising strategy to combat retinal disease (news, 13 March 2025) available at: ophth.wisc.edu/blog/2025/03/13/gamm-pig-retinal-cells/ [accessed March 2025].
