In vitro culture characteristics of corneal epithelial, endothelial, and keratocyte cells in a native collagen matrix

The objective of this investigation was to demonstrate the effectiveness of a tissue-engineered collagen sponge as a substrate for the culture of human corneal cells. To that end, human kerotocyte, epithelial, and endothelial cells were cultured separately on collagen sponges composed of native fibrillar collagen with a pore size of approximately 0.1 mm. Co-culture experiments were also performed (epithelial/endothelial and epithelial/keratocyte cultures). Proliferation of keratocytes and matrix production was assessed. The morphology of the epithelial and endothelial cell cultures was characterized by histology and scanning electron microscopy. Keratocytes cultured on collagen sponges exhibited increased matrix synthesis over time as well as proliferation and repopulation of the matrix. Epithelial and endothelial cells showed the ability to migrate over the collagen sponge. The thickness of the epithelial layer was influenced by soluble factors produced by endothelial cells. The morphology of the bottom layer of epithelial cells was influenced by the presence of keratocytes in the culture. These studies indicate that human corneal cells exhibit normal cell phenotype when cultured individually on an engineered collagen sponge matrix and co-culture of different cell types in the cornea can influence cell behavior.