AIM To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. proliferation of the corneal epithelial or endothelial cells or on TNFRSF11A the keratocytes. The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea (APC) transplantation. The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer. CONCLUSION We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft. Keywords: ostrich, acellular corneal stroma, tissue engineering, cornea INTRODUCTION Corneal transplantation is presently the only effective method for the visual rehabilitation of patients with corneal blindness. However, there is an increasing need for human donor corneal tissue and a shortage of suitable cornea donors. Therefore, many researchers have attempted to fabricate alternatives to donor corneas for the treatment of corneal blindnessC. Recently, new scaffolds for tissue engineering based on native tissues have become an attractive option. The primary objectives of preparing a decellularized extracellular Chloramphenicol manufacture matrix (ECM) are to eliminate Chloramphenicol manufacture tissue immunogenicity and retain the three-dimensional spatial structure of the ECM of native tissues. Acellular porcine corneas (APCs) are composed of natural stromal proteins that exhibit reasonable structural characteristics. Several research groups have succeeded in preparing a porcine acellular corneal stroma using detergent and/or several enzymesC. The five largest eyes in the vertebrate kingdom are those of the whale, elephant, zebra, giraffe and ostrich. The axial length of the eye in these species ranges from 54 mm in the baleen whale to 39 mm in the ostrich. The ostrich cornea is large enough to be trimmed to fit the human eye and ostrich corneas are an abundant resource. The goal of this study was to use an acellular ostrich cornea (AOC) stroma to replace an APC as a new scaffold to construct a tissue-engineered cornea (TEC). We hope that the AOCs will prove to be a potential solution to the short supply of donor corneas. MATERIALS AND METHODS Animals Whole ostrich eyes (either gender, 12 months old, weighing 60-70 kg) and Yorkshire Landrace pig eyes (either gender, 6 months old, weighing 120-150 kg) were obtained within 1-3h of postmortem and subjected to a decellularization procedure within 2h of receipt. The native ostrich corneas/porcine corneas with 2 mm scleral rings were removed with a pair of curved scissors. Young adult New Zealand white rabbits (either gender, 10 weeks old, weighing 2-3 kg) were used as animal transplant models. All animal experiments conformed to the Association for Research in Vision and Ophthalmology statement for the use of animals in ophthalmic and vision research. Preparation of Acellular Ostrich Corneas The above corneoscleral tissues were rinsed three times with phosphate buffered saline (PBS). Then, a lamellar cornea stroma with a diameter of 12 mm ring and thickness of 400 microns was acquired by scaled trephine under an ophthalmologic microscope (Olympus, Japan). Subsequently, the lamellar cornea was soaked in hypertonic saline solution with 20% NaCl Chloramphenicol manufacture (w/v) for 48h at 37C. Next, the corneal grafts were immersed in 0.13% trypsin solution (GIBCO,USA) or trypLE? Express (1) solution (GIBCO) for 48h at 37C and then washed in ultrapure water 3 times for 30min each time. Finally, the grafts were put into a sealed dry container and dehydrated with calcium chloride for 1-2d at room temperature. The prepared AOCs were sealed in sterile plastic envelopes, sterilized by g-irradiation (25 kGy) and stored at 4C until used. Hematoxylin and Eosin Staining Native corneas (ostrich, human and porcine) and transplanted corneas were collected and examined with hematoxylin.