Abstract
Purpose: :
The retinal pigment epithelium (RPE) plays an important role in maintaining a healthy neural retina. With changes due to age, morbidity or, CNV removal, damage or defects of the RPE occur. Under these conditions, RPE cells do not proliferate, but only undergo lateral expansion. Therefore, RPE transplantation has been attempted to repair the damaged RPE. In the present study we transplanted tissue engineered RPE cell sheets harvested from temperature–responsive dishes in a rabbit model.
Methods: :
1. Fabrication of transplantable RPE cell sheets RPE cells were harvested from pigmented rabbit eyes and seeded on temperature responsive dishes modified with the temperature responsive polymers,poly(N–isopropylacrylamide). Pigmented RPE cell sheets were noninvasively harvested without enzymatic treatment, by reducing the culture temperature.
2. Transplantation of RPE cell sheets into the subretinal space
Using 3–port vitrectomy RPE cell sheets were transplanted into the subretinal space of albino rabbits. 9 days after surgery the rabbits were sacrified and the eyes were enucleated and examined by histology and electron microscopy.
Results: :
Cultured RPE cell sheets were monolayered with a cobblestone cell shape characteristic of the native RPE. The cultured RPE cell sheets also expressed Cytokeratin 18, a marker of the native RPE. After transplantation, the RPE cell sheets attach to the host tissues in the subretinal space, more effectively than with the injection of isolated cell suspensions. Although the cell sheets maintain a monolayer structure in most areas, they are slightly folded or wrinkled in some regions.
Conclusions: :
RPE cell sheets that resemble the native monolayer could be created. Tissue engineered RPE cell sheets harvested from temperature–responsive culture dishes could be effectively transplanted beneath the neural retina.
Keywords: retinal pigment epithelium • transplantation • retinal culture