Ex Vivo Construction of an Artificial Ocular Surface by Combination of Corneal Limbal Epithelial Cells and a Compressed Collagen Scaffold Containing Keratocytes

We have investigated the use of a laminin-coated compressed collagen gel containing corneal fibroblasts (keratocytes) as a novel scaffold to support the growth of corneal limbal epithelial stem cells. The growth of limbal epithelial cells was compared between compressed collagen gel and a clinically proven conventional substrate, denuded amniotic membrane (AM). Following compression of the collagen gel, encapsulated keratocytes remained viable and scanning electron microscopy showed that fibers within the compressed gel were dense, homogeneous, and similar in structure to those within denuded AM. Limbal epithelial cells were successfully expanded upon the compressed collagen, resulting in stratified layers of cells containing desmosome and hemidesmosome structures. The resulting corneal constructs of both the groups shared a high degree of transparency, cell morphology, and cell stratification. Similar protein expression profiles for cytokeratin 3 (CK3) and CK14 and no significant difference in CK12 mRNA expression levels by real-time polymerase chain reaction were also observed. This study provides the first line of evidence that a laminin-coated compressed collagen gel containing keratocytes can adequately support limbal epithelial cell expansion, stratification, and differentiation to a degree that is comparable to the leading conventional scaffold, denuded AM.