[Cryopreservation of porcine corneas with chondroitin sulfate]

A new method for cryopreservation of porcine corneoscleral discs has been developed. Instead of the widely used cryoprotectant DMSO, chondroitin sulfate was applied as a cryoprotectant for the first time. Post-thawing evaluation was done after short-term tissue culture. Central cell counts showed a mean endothelial cell density of 2430 cells/mm2 (+/- 383) after freezing with a combination of 2% chondroitin sulfate and 20% fetal calf serum. Corneae which were cryopreserved with DMSO using the method established by Capella and Kaufman showed a mean endothelial cell density of 1672 cells/mm2 (+/- 617). These experiments demonstrated significant cryoprotective properties of chondroitin sulfate. In addition to its application in refrigerated corneal storage at 4 degrees C and organ culture at 32 degrees C, this substance may also be useful in cryopreservation.