Differentiation of Induced Pluripotent Stem Cells to Neural Retinal Precursor Cells on Porous Poly-Lactic-co-Glycolic Acid Scaffolds

Abstract

Purpose: Cell replacement therapy for the treatment of retinal degeneration is an increasingly feasible approach, but one that still requires optimization of the transplantation strategy. To this end, various polymer substrates can increase cell survival and integration, although the effect of their pore size on cell behavior, particularly differentiation, has yet to be explored. Methods: Salt crystals of varying known size were used to impart structure to poly(lactic-co-glycolic acid) (PLGA) scaffolds by a salt leaching/solvent evaporation process. Mouse induced pluripotent stem cells (miPSCs) were seeded to the polymer scaffolds and supplemented with retinal differentiation media for up to 2 weeks. Proliferation was measured during the course of 2 weeks, while differentiation was evaluated using cell morphology and expression of early retinal development markers. Results: The salt leaching method of porous PLGA fabrication resulted in amorphous smooth pores. Cells attached to these scaffolds and proliferated, reaching a maximum cell number at 10 days postseeding that was 5 times higher on porous PLGA than on nonporous controls. The morphology of many of these cells, including their formation of neurites, was suggestive of neural phenotypes, while their expression of Sox2, Pax6, and Otx2 indicates early retinal development. Conclusions: The use of porous PLGA scaffolds to differentiate iPSCs to retinal phenotypes is a feasible pretransplantation approach. This adds to an important knowledge base; understanding how developing retinal cells interact with polymer substrates with varying structure is a crucial component of optimizing cell therapy strategies.

Combining Stem Cells and Biomaterial Scaffolds for Constructing Tissues and Cell Delivery

“…PGLA scaffolds can be combined with different types of stem cells, including MSCs, ESCs, and iPSCs to engineer a wide range of tissues, including muscle, bone, cartilage, and nerve [204][205][206][207][208][209]. The scaffold porosity, topography, mechanical properties, and drug delivery capacity all serve as important variables when designing such scaffolds.…”

Optimizing Donor Cellular Dissociation and Subretinal Injection Parameters for Stem Cell-Based Treatments

“…Our laboratory previously demonstrated that (a) iPSC‐derived photoreceptor precursor cells integrate within the outer retina of retinal degeneration mouse models and that (b) transplantation on polymeric cell support scaffolds is superior to cell injection alone . Herein, we describe the isolation of patient‐derived RPCs from 3D retinal organoids at 60‐days postdifferentiation.…”

Two-photon polymerization for production of human iPSC-derived retinal cell grafts

“…Two-dimensional scaffolds with randomly distributed pores remain a popular investigatory option; solvent casting, electrospinning and molecular templating are all readily available and relatively simple fabrication techniques [11, 28–32]. However, the structures fabricated with any of these methods fail to provide proper vertical guidance to transplanted cells.…”