Development of a Bioengineered Corneal Endothelial Cell Sheet to Fit the Corneal Curvature

PURPOSE To evaluate a novel bioengineered corneal endothelial cell sheet that fits the curvature of the posterior corneal surface. METHODS A spherically curved gelatin hydrogel sheet (SCGS) was prepared by the dehydrothermal cross-linking method, and its permeability to water and protein was tested. Monkey corneal endothelial cells (MCECs) were seeded onto these hydrogel sheets, and the cells were examined by immunohistochemistry. Then MCEC-SCGS constructs were transplanted in monkeys with bullous keratopathy to assess the efficacy of the hydrogel sheets as a scaffold. RESULTS The hydrogel sheets showed similar permeability to water and protein as that of atelocollagen and vitrigel sheets. After transplantation, the SCGS did not show wrinkling and adhered tightly to the posterior corneal surface, whereas the flat sheets developed wrinkles that inhibited tight adhesion. Monkey corneal endothelial cells grown on hydrogel sheets expressed anti-zonula occludens-1 (ZO-1), N-cadherin, and sodium, potassium, and adenosine triphosphatase (Na,K-ATPase) along the plasma membrane. In a monkey model of bullous keratopathy, transplanted MCEC-SCGS constructs showed good adhesion to the posterior corneal surface, with subsequent improvement of corneal edema and transparency. CONCLUSIONS A novel MCEC-SCGS construct was effective in a monkey model of bullous keratopathy. The SCGS achieves close adhesion to the posterior corneal surface without wrinkling and may contribute to clinical transplantation of corneal endothelial cell sheets.