Characterization of cultured human RPE grown on a thin collagen substrate

Purpose. Histopathologic studies suggest that dysfunction of the retinal pigment epithelium (RPE) may be the primary source of injury in ARMD. Replacement of diseased RPE by transplantation of healthy RPE is an attractive approach to a possible treatment of this disease. The best method of transplanting cultured RPE may prove to be as a confluent monolayer. Methods. A type I collagen membrane, approximately 0.5 microns in thickness was used to span a hole cut in the surface of a Falcon cell culture insert. Early passage (PI and P2) cultured human RPE cells were plated on these thin collagen membranes previously coated with a layer of extracellular matrix (usually fibronectin). These cells were prepared for examination by EM and immunofluorescence. Results. Early passage human RPE cells grown to confluence on the collagen morphologic features more typical of m situ cells when compared to late passage cells examined previously. Immunofluorescent preparations of the RPE cells grown on the membrane labeled with anti-ZO-1 antibody revealed a pattern of membrane-specific staining suggestive of tight junction formation. Conclusions. We are continuing to perfect a method of growing human RPE cells on a very thin type I collagen membrane. This may prove to be an ideal substrate for growing RPE cells as a monolayer prior to transplanting them into the subretinal space.