Evaluation of 2 ex vivo Bovine Cornea Storage Protocols for Drug Delivery Applications.

The use of corneal tissue for ex vivo therapeutic evaluations is limited due to its rapid loss of viability after excision. Optimization of storage conditions may allow prolonged retention of physical tissue properties. In this study, we evaluated how storage in optimized organ culture (OC) medium at 37°C or phosphate-buffered saline (PBS) at 2-8°C impacted physical properties of bovine corneas. Tissue hydration, permeability and histology were monitored at baseline and following 1, 4 and 7 days of storage. Corneas stored in OC demonstrated significantly higher hydration and permeability when compared to those stored in PBS. Histology revealed that storage in OC consistently caused detachment of the epithelial layer by day 4 of storage, whereas both storage conditions caused a significant increase in stromal thickness and tissue vacuolation. This study highlights the limitations of currently available corneal tissue storage approaches for ex vivo drug permeation studies.