Abstract
Purpose The transplantation of RPE cells is believed to be one of the primary ways to restore the RPE functionality in diseases such as age-related macular degeneration. The way for these cells to withstand the degenerative environment created by disease conditions is still under investigation. Ex-vivo models of aged human Bruch’s membrane could represent a powerful tool to study the ability of implanted RPE cells to tackle these pathological conditions.
Methods Bruch’s membrane explants (6 mm) were prepared from eyes of 30 human donors (age range > 65 years old) by gently removing native RPE cells with ddH2O to expose the RPE cell basal lamina. Pluripotent-derived RPE cells were plated over a biological or artificial scaffold, respectively, prior to explant cultivation. RPE cells cultivated on vitronectin-coated tissue culture wells were taken as control. Explants were then examined histologically or analyzed with scanning electron microscopy.
Results RPE cell reattachment was affected when culturing RPE cells on aged human Bruch’s membrane explants. Cell morphology worsened by day 14 when the cells started to dedifferentiate. On the contrary, the two scaffolds tested significantly improved the pluripotent derived-RPE survival on BM, regardless of the initial condition of the explant. Moreover, only RPE cells initially cultured on scaffolds showed proper maturation and correct polarization.
Conclusions This assay provides an ex vivo model of aged Bruch’s membrane to assess the viability and functional characteristics of pluripotent derived-RPE cells when seeded on aged/compromised extracellular matrix. These results suggest that the ability of the RPE cells to repopulate Bruch’s membrane in age-related macular degeneration is preserved when the cells are cultivated over a suitable scaffold.
