Hrebenyk I. The effect of different preservation methods on morphofunctional properties of porcine cornea

The thesis is dedicated to the study of morphofunctional properties of normal porcine cornea and of the effects on it of cryopreservation and lyophilization. Complex morphological studies established that cryopreservation with the use of a cryoprotectant permits to maintain a high degree of structural corneal integrity. With the use of this method the morphometric indices such as thickness of the entire cornea, anterior epithelium, and substantia propria do not differ significantly from the respective indices of a normal porcine cornea. Lyophilization following cryopreservation with the use of a cryoprotectant permits to decrease the degree of structural corneal damage and to achieve better preservation of plasmatic, nuclear and organoid membranes of keratocytes and epithelial cells. Morphometric indices alter to a lesser extent than after ordinary lyophilization. Cryopreservation and lyophilization with the use of a cryoprotectant permit to retain sufficient concentrations of biochemical substances (glycosaminoglycans, hyaluronic acid, chondroitin sulfate, sialic acids). Preliminary luminescence analysis of cryopreserved with the use of a cryoprotectant and lyophilized xenocornea revealed a high level of nucleic acids, a marker of its sustained potential for regeneration.