Processing porcine cornea for biomedical applications

To investigate the propriety of decellularized porcine corneas as a source of lamellar corneal xenografts, we treated porcine corneas with (1) freezing, (2) three freezing-thawing, (3) hypertonic saline, (4) hyperosmolar glycerol, (5) trypsin/sodium dodecyl sulfate/Dispase, and (6) DNase/RNase. After processing, we examined the cells and collagen structures of the decellularized corneas using hematoxylin-eosin staining, terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and transmission electron microscopy. Cell viability was also assessed via organ culture. In addition, the outcomes of porcine anterior lamellar corneal xenografting were evaluated in rabbits. Graft integration and corneal thickness were assessed using anterior optical coherence tomography, and the corneas were histologically examined sequentially after transplantation. We found that porcine corneas treated with hypertonic saline-based decellularization had little immunogenicity with intact collagen structures. The porcine corneal xenografts decellularized with the hypertonic saline-based method were well integrated into the adjacent host tissues and remained clear in rabbit eyes for more than 6 months.