Development of a retinal engineered tissue for the treatment of retinal degenerative disorders

Abstract

Purpose : Retinitis Pigmentosa (RP) and Age-related macular degeneration (AMD) are both degenerative diseases that may lead to blindness and for which few therapeutic options are available. Depending on the stage and the nature of the disease, different cell types are affected and will ultimately die including photoreceptors (PRs) and in some cases retinal pigment epithelial (RPE) cells. Cell therapy (CT) is an attractive alternative to treat these diseases by replacing dead or dysfunctional cell types. Human pluripotent stem cells (hPSCs) represent a viable unlimited source of retinal cells for cell therapy. However, a key issue to achieve an in vivo retinal reconstruction resides on the pharmaceutical formulation of the cell therapy as an organized tissue prior implantation. To reconstruct in vitro this retinal tissue composed of PRs and RPE cells, we developed three-dimensional (3D) scaffolds. We have designed these microstructured polymeric scaffolds with micropores opened on both ends that are expected to guide PR maturation and organization.

Methods : To produce these scaffolds, we have developed a molding process with master molds (the negative of the desired structure) generated by a method of two photons lithography. Once this mold produced, the desired polymer (in a liquid state) is poured on top of it. A thin microstruturated membrane is finally obtained. To validate the 3D scaffold function for tissue reconstruction, we have derived RPE cells and PRs from hPSCs. Photoreceptors were obtained from the differentiation of hPSCs into retinal organoids. After 120 days of differentiation, organoids were dissociated and seeded on the top of microstructured scaffolds, which on top of RPE epihtelium

Results : We demonstrated that PRs developed a polarized morphology inside micropores, as evaluated by CRX and Recoverin expressions.

Conclusions : Future work will address the functionality of this retinal engineered tissue in rodent models of retinal degeneration.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.