Inner limiting membrane as membranous support in RPE sheet-transplantation

Purpose: To investigate the inner limiting membrane as a scaffold for retinal pigment epithelium cells (RPE). Methods: Human donor eyes (n = 10) from the Eye Bank Tübingen were used to collect the inner limiting membrane (ILM). These human donor eyes and additional porcine eyes (n = 11) served to isolate RPE cells. A human RPE cell line (ARPE-19) was used as control. RPE cells were cultured on ILM for 3 and 7 days. Phase-contrast photographs of the cells in culture were obtained. Morphology and ultrastructural changes were evaluated by light and transmission electron microscopy. Results: Porcine RPE cells adhere and proliferate when seeded on human ILM. The cells maintained their cuboidal morphology, were polarized, disclosed microvilli on the apical surface, formed intercellular junctions and did not dedifferentiate. Human RPE cells obtained from cadaver eyes barely adhered to the ILM and did not form an intact monolayer. ARPE-19 cells formed a dense colony and maintained epithelial features. Conclusion: The ILM is an ideal matrix to establish an intact RPE monolayer and has the potential to be used as sheet for subretinal transplantation.