Functional 3-Dimensional Retinal Organoids: Technological Progress and Existing Challenges.

Meimanat Fathi,Cody T. Ross,Zohreh Hosseinzadeh

doi:10.3389/fnins.2021.668857

Meimanat Fathi, Cody T. Ross + Show 1 more

Open Access

https://doi.org/10.3389/fnins.2021.668857

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Abstract

Stem cell scientists have developed methods for the self-formation of artificial organs, often referred to as organoids. Organoids can be used as model systems for research in multiple biological disciplines. Yoshiki Sasai’s innovation for deriving mammalian retinal tissue from in vitro stem cells has had a large impact on the study of the biology of vision. New developments in retinal organoid technology provide avenues for in vitro models of human retinal diseases, studies of pathological mechanisms, and development of therapies for retinal degeneration, including electronic retinal implants and gene therapy. Moreover, these innovations have played key roles in establishing models for large-scale drug screening, studying the stages of retinal development, and providing a human model for personalized therapeutic approaches, like cell transplants to replace degenerated retinal cells. Here, we first discuss the importance of human retinal organoids to the biomedical sciences. Then, we review various functional features of retinal organoids that have been developed. Finally, we highlight the current limitations of retinal organoid technologies.

Highlights

The retina is a thin (∼0.25 mm) layer of neurons in the back of the eyeball—it is a part of the central nervous system that grows inside of the eye during development
Organoids derived from induced pluripotent stem cells, or embryonic stem cells (ESCs), have been used by researchers to create in vitro tissues that mimic their natural counterparts, Functional 3-Dimensional Retinal Organoid Technology advancing medical research in the 1980s and beyond (Shannon et al, 1987)
Lab-grown retinal organoids are composed of several types of cells organized in a physiologically and morphologically complex manner (Eiraku et al, 2011)

Summary

INTRODUCTION

The retina is a thin (∼0.25 mm) layer of neurons in the back of the eyeball—it is a part of the central nervous system that grows inside of the eye during development. Retinal organoids can be used to study retinal degeneration, human retinal implants, optogenetics and gene therapies, drug screening and toxicity, and the stages of retinal development. 2D retinal culture may not emulate important naturalistic aspects of native retinal cells in vivo, and fails to entirely recapitulate the morphology and functional physiology of the human retina. Animal models are another widespread tool that can be used to study retinal diseases and develop treatments—e.g., through genetic or interventional modifications (Volobueva et al, 2019).

F Drug screening

B Visual cycle

Findings

CONCLUSION