Natural and artificial substrates for retinal pigment epithelial monolayer transplantation

The aim of this study was to culture retinal pigment epithelial (RPE) cells on natural and synthetic substrates for future use in RPE monolayer transplantation in the eye. The extracellular capsules surrounding the human lens and a hydrogel biomaterial were used as substrates for monolayer culture. All materials were seeded with either pig or human retinal pigment epithelial cells and were maintained in tissue culture conditions. Upon confluency, the cell density was calculated and cell viability determined. All monolayers were stained with phalloidin–rhodamine for F-actin and antibodies to tight junction-associated protein, ZO1. The final cell density of human RPE monolayers on the hydrogel and lens capsule was 3200±187 and 3350±120 cells/mm2 respectively. Pig RPE cells had a final cell density of 3740±205 cells/mm2 on the lens capsule and 3025± cells/mm2 on the hydrogel. F-actin staining revealed a circumferential ring of actin filaments in all the cells grown on substrates. ZO1 immunohistochemisty demonstrated staining along the lateral cell borders of all cell types. The successful culture of RPE cells on these substrates may have the potential for transplanting cell monolayers in the eye to improve outcomes for degenerative diseases in the retina.