Transplantation of tissue-engineered retinal pigment epithelial cell sheets in a rabbit model.

The retinal pigment epithelium (RPE) plays an important role in maintaining a healthy neural retina. With changes due to age, morbidity or removal of choroidal neovascularis developed as a means ofation, damage or defects of the RPE occur. Accordingly, RPE transplantation techniques have been repairing the damaged RPE. We conducted a study to transplant tissue-engineered RPE cell sheets in a rabbit model. RPE cells were isolated from pigmented rabbit eyes and seeded on temperature-responsive culture surfaces. Cultured RPE cells were arranged as a monolayer with a cobblestone cell shape that is characteristic of native RPE. The pigmented RPE cell sheets were non-invasively harvested without enzymatic treatment simply by reducing the culture temperature. Using 3-port vitrectomy, RPE cell sheets were transplanted into the subretinal space of albino rabbits. Seven days after surgery, the rabbits were sacrificed, and the eyes were enucleated and examined under both light and electron microscopy. After transplantation, our results show that the RPE cell sheets attached to the host tissues in the subretinal space more effectively than with the injection of isolated cell suspensions. Although the cell sheets maintained a monolayer structure in most areas, they were slightly folded or wrinkled in some regions. We conclude that tissue-engineered RPE cell sheets harvested from temperature-responsive culture dishes can be effectively transplanted beneath the neural retina.