Decellularization of porcine corneas and repopulation with human corneal cells for tissue-engineered xenografts

Purpose: To evaluate the potential use of decellularized porcine corneas (DPCs) as a carrier matrix for cultivating human corneal cells in tissue engineering. Methods: Corneal cells were isolated from human corneoscleral rims. Porcine corneas were decellularized using hypotonic tris buffer, ethylene diamine tetraacetic acid (EDTA, 0.1%), aprotinin (10 KIU/ml) and 0.3% sodium dodecyl sulphate. Haematoxylin-eosin (HE) and 4,6-diamidino-2-phenylindole (DAPI) staining were performed to confirm removal of the corneal cells. Quantitative analysis was performed to determine levels of desoxyribonucleic acid (DNA) using DNA Purification Kit (Fermentas, St. Leon-Rot, Germany). Alcian blue staining was carried out to analyse the structure of the extracellular matrix (ECM). Corneal stromal cells were injected into the DPCs; limbal corneal epithelial cells and corneal endothelial cells were seeded onto the anterior and posterior surfaces of the DPCs, respectively. Evaluation was undertaken at days 14 and 30. The phenotypical properties of the cultivated corneal cells were investigated using Immunolocalization of type I collagen, keratocan, lumican, cytokeratin 3 (AE5) and type VIII collagen. Results: Haematoxylin-eosin and DAPI staining showed efficient elimination of porcine corneal cells, whereas alcian blue confirmed gross preservation of the ECM. The quantitative analysis of the DNA content showed a significant reduction (mean before decellularization: 75.45 +/- 13.71 ng/mg; mean after decellularization: 9.87 +/- 2.04 ng/mg, p < 0.001). All three types of corneal cells were efficiently cultured and expanded on the DPCs. Conclusions: Decellularized porcine corneas might serve as a potential scaffold for tissue engineering of the cornea, possibly providing xenogenic substrate for corneal transplantation.