Device-free isolation of photoreceptor cells from patient iPSC-derived retinal organoids

Autologous photoreceptor cell replacement is one of the most promising strategies currently being developed for the treatment of patients with inherited retinal degenerative blindness. Induced pluripotent stem cell-derived (iPSC-derived) retinal organoids, which faithfully recapitulate the structure of the neural retina, are an ideal source of transplantable photoreceptors required for these therapies. However, retinal organoids contain other retinal cell types, including bipolar, horizontal, and amacrine cells, which are unneeded and may reduce the potency of the final therapeutic product. Therefore, approaches for isolating fate-committed photoreceptor cells from dissociated retinal organoids are desirable. In this work, we present partial dissociation, a technique that leverages the high level of organization found in retinal organoids to enable selective enrichment of photoreceptor cells without the use of specialized equipment or reagents such as antibody labels. We demonstrate up to 90% photoreceptor cell purity by simply selecting cell fractions liberated from retinal organoids during enzymatic digestion in the absence of mechanical dissociation. Since the presented approach relies on the use of standard plasticware and commercially available current good manufacturing practice-compliant reagents, we believe that it is ideal for use in the preparation of clinical photoreceptor cell replacement therapies.