Decellularized Matrix for Corneal Tissue Engineering: Recent Advances in Development and Clinical Potential
The worldwide shortage of donated human corneas for transplantation is a serious problem. Induced pluripotent stem (iPS) cells have yielded new possibilities for regenerating the corneal epithelium and endothelium, which consist only of cells. However, regeneration of the corneal stroma, which accounts for approximately 90% of the entire corneal thickness, has not yet achieved fully satisfactory results despite much effort. This might be because the corneal stroma possesses a highly ordered, stacked hierarchical structure, which contributes to the maintenance of corneal transparency as well as its mechanical properties. Currently, the decellularized cornea has received considerable attention for use as an artificial corneal stroma. The decellularized cornea is an extracellular matrix (ECM) from which cellular components and other immunogens have been removed, but which maintains the structural and mechanical integrity of the corneal stroma. This chapter summarizes decellularization techniques for the preparation of decellularized corneal matrices, the clinical potential of xenotransplantation with grafts of decellularized corneal matrices, and the recent advances in and limitations of commercially available decellularized corneal matrices. Finally, we summarize research on the decellularized cornea and discuss future perspectives to realize fully functional bio-engineered corneas to replace donated human corneas.