Evaluating Descemet’s Membrane as a Scaffold for Retinal Pigment Epithelium-Based Therapies in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of central vision loss in industrialized countries and is characterized by progressive degeneration of the retinal pigment epithelium (RPE). In the dry form of the disease, the progressive dysfunction of the RPE and Bruch’s membrane severely compromises photoreceptor survival and retinal homeostasis. At the same time, current pharmacological treatments remain limited in efficacy. For this reason, stem cell-derived RPE transplantation has emerged as a promising strategy, with human induced pluripotent stem cells (iPSCs) representing an optimal source of RPE, as they allow the generation of patient-specific cells while avoiding the ethical concerns associated with embryonic stem cells. Nevertheless, the success of such transplantation critically depends on the scaffold, which must support adhesion, organization, and functional maturation of the grafted cells. Descemet’s membrane, due to its structural and biochemical properties and its accessibility from donor tissue, has been proposed as a scaffold for RPE cell transplantation. This project aims to evaluate the suitability of decellularized Descemet’s membrane for RPE reconstruction in comparison with synthetic scaffold, already used in clinical applications, namely poly (lactic-co-glycolic acid) (PLGA). In this study, human Descemet’s membranes were dissected from donor corneas and subjected to a decellularization protocol based on osmotic shock, in which constant agitation in distilled water promotes cell lysis and removal of nuclear material while preserving the extracellular matrix architecture. Human iPSC-derived RPE cells were seeded on decellularized Descemet’s membrane, native Bruch’s membrane, and PLGA membranes. Morphological analysis assessed cell adhesion, pigmentation, and epithelial organization, while immunofluorescence confirmed the expression of characteristic RPE markers, including, RPE65, CRALBP, BEST1, MERKT, ZO-1, PMEL, TYRP1, MITF, and P-EZRIN. To evaluate functional properties, transepithelial electrical resistance (TEER) was measured. As a final step, ELISA assays were performed to evaluate the polarized secretion of VEGF and PEDF as a hallmark of functional RPE polarization. The decellularization protocol applied to Descemet’s membrane ensured the efficient removal of approximately 99.8% of DNA while preserving key extracellular matrix proteins, thereby maintaining scaffold integrity. As a result, the decellularized membrane was able to support the development of a functional retinal pigment epithelium. TEER analysis showed 1 values consistent with the formation of an intact and polarized epithelial barrier. Immunostaining and ELISA confirmed a comparable and robust expression of key RPE markers and secreted factors, indicative of appropriate cellular identity and functionality, in iPSC-derived RPE seeded on both PLGA and Descemet’s membrane. Taken together, these findings highlight decellularized Descemet’s membrane as a promising scaffold for retinal pigment epithelium-based therapies, offering a valuable opportunity for consideration in the context of regenerative approaches for age-related macular degeneration.