Development of alternative strategies for preservation and generation of corneal tissues for transplantation

Abstract

Many corneal diseases can only be treated through keratoplasty, a corneal transplantation whose access is dependent on the limited availability of transplantable donor corneas. To increase the number of corneal tissues, this thesis investigated alternative preservation methods and alternative sources of transplantable corneal tissues. The first objective was to investigate the effect, on human corneas, of cryopreservation protocols using dimethyl sulfoxide (DMSO) with (P1) and without albumin (P2), and of vitrification protocols without (P3) and with formamide (P4). The second objective was to engineer new transplantable tissues using Descemet’s membranes (DMs) and human endothelial cells (hECs) isolated from discarded corneas which were unfit for clinical use. Results showed that only P1 provided corneas with viable ECs and a slightly distorted general structure, but variability among C1-cryorpeserved corneas did not allow to use this protocol in the clinical practice. A corneal graft was successfully engineered using discarded corneas with an intact decellularized DM seeded with primary hECs. However, a fully functional endothelium was not observed within the timeframe used in this study. Consequently, additional research will be needed to improve both approaches for clinical applications. In the future and after further studies, these approaches would represent promising alternatives to improve the availability of transplantable corneal tissues and the access to keratoplasty.