Tissue engineered corneal endothelial grafts using methacrylated poly-epsilon-lysine hydrogels and cultured human corneal endothelial cells

Abstract

Purpose : The global donor cornea shortage has led to the development of alterative solutions such as tissue engineered grafts using cultured corneal endothelial cells (CECs). We have previously shown that poly-epsilon-lysine (PeK) based hydrogels demonstrate good compatibility with CECs, are handleable and are able to function to thin an oedematous cornea to near control levels after 3 weeks in a rabbit in vivo model. However, manufacture of these hydrogels with an optimal thickness of <100um was not possible using this formulation. We have now synthesised a methacrylated PeK (PeKMA) to allow crosslinking using UV light and production of thinner gels.

Methods : The peptide PeK, was modified by covalent functionalisation with methacrylamide residues to achieve customisable, noncytotoxic UV crosslinked hydrogel networks. The PeKMA hydrogels were evaluated mechanically by compression, stress relaxation for viscoelasticity, and transparency for use as a corneal graft. Hydrogels were seeded with a human corneal endothelial cell line, porcine corneal endothelial cells and human corneal endothelial cells at a density of 1800cells/mm². Cells were investigated for attachment and monolayer formation over 7 days and characterised immunochemically using ZO-1 and Na+K+ATPase

Results : The hydrogels can be loaded into a clinical delivery device and delivered to the anterior chamber in a porcine ex vivo model. The hydrogels have a compressive peak stress of 0.055MPa and a transparency of over 90%. All 3 cell types grow on the surface of the hydrogels and form confluent monolayers expressing ZO-1 at cell junctions and Na+K+ATPase on the cell surface.

Conclusions : PeKMA hydrogels can be produced that show properties of high transparency, cell compatibility and are easy to handle. Use of this newly formulated PeKMA hydrogel allows production of multiple corneal endothelial grafts from one donor cornea. The graft could be used as a surgical therapy to treat endothelial related eye diseases aiming to decrease the current long waiting times for patients.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.